Yes, sure, clinging on to certain kinds of unrealistic expectations, in certain contexts (particularly personal relationships), can be fatal.
But this is a truism that any idiot could tell you - and in this case the post is generalized to the point of meaninglessness.
Suppose you encounter someone who is openly racist, dishonest or technically incompetent at their job, and no one is challenging him about it. Because it's bad to have expectations about public & professional behaviour, and even worse to actually impose them on others!
Here's the core message: when the world isn't how you think it should be, don't have the courage to try and change it, or to speak out about how you feel. Suppress your feelings, accept everything just the way it is, and - just as long as you yourself behave well - all the bad energy will go away!
Sounds to me like someone trying to justify being a total wimp. Like someone who's so afraid of experiencing any degree of anger or disappointment that they philosophize their way to vapidity and numbness. And I'm afraid that's my overall impression of people who embrace "zen" as a lifestyle paradigm, (rather than just a mindset for, say, a discrete programming project, for which it can work wonderfully). Zen has its place, but taken too far it becomes morally corrosive, and turns personalities to mud.
I've met folks who live this way. They are not wimps. They are strong, and resilient.
What is a wimp? More like, someone who is afraid, who lashes out at things before they understand them, staying in their disfunctional rut rather than risk any emotion other than anger.
Why is it bad to constantly challenge yourself and the world around you. Humans are great because they can change the circumstances and not to surrender to them. Although often times it comes through terrible mistakes, but the process is moving forward.
Telling someone that they are ignorant or incompetent is far more effective when you're not hinged on whether or not they will listen to you. If you are attached to the result, you will become a dictator. If you are not, you will become the most effective type of leader. It is far more effective to give someone the message and trust them to figure it out then to force them to change when they either don't want to or are not yet capable. If one person hits a bottleneck, there are millions of others who are capable of taking their next step with a little guidance from you.
I completely agree that a lot of people fall into the trap you described.
I think I am guilty of further polarizing what was presented as a false dichotomy in the first place. It is not the case that either we live a life full of expectations that poison us when they are not met; or that we must be devoid of expectation and experience all outcomes with equanimity. Shades of grey predominate.
That was really my beef with the article: its absolutism. Life requires a repertoire of attitudes and responses. It is futile and naive to say we must always adopt a principle of throwing all our expectations away. It is not so different from saying that the culture and technology we treasure could have been more painlessly attained in a world of wandering sadhus.
The interesting thing is that detachment does not remove the shades of grey, it's not about removing anything and more about accepting it. It's the difference between having a favorite colour and having every colour as your favorite. In the latter case, you don't care what the weather is, you're still smiling.
In a world of wandering sadhus there wouldn't any development of culture and technology since they would all be dedicated to reaching enlightenment, which means that none of them would have attained it. It would be a world of people with the same goal which nobody has actually achieved.
I think that after enlightenment has been attained, people do the same things as we do now, just with infinitely less friction. The saying goes - "Before enlightenment, chop wood, carry water. After enlightenment, chop wood, carry water." Some minds are inclined towards science or cultural development or computer programming and the same would apply to them.
I've often felt that the Buddhist "no desires" and "no mind" concepts are akin to the trivial solution in polynomials or vector math: set everything to 0!
That it's one solution does not mean there are not other, non-zero solutions.
Buddhism simply asserts that what you think is your reality, isn't. That's not to say that NOTHING is real or that you don't experience something, it's to say what you put stock in is very much not worth doing so.
My main point, though, is in striving to be desire-free. (To the adept, this is an upaya, a clever means of potentially pointing out the truth, not the truth itself. However, it's an oft used one.) In the case of this article, being desire-free is translated into being expectation-free. They're the same idea to the author.
I'm not discussing what reality is here, or what it is not, but am looking at the idea that desire causes suffering. I've imagined this phrased as a set of coefficients indicating quantity for all desires in the world, i.e. x1 is how much you have desire d1:
x1 * d1 + x2 * d2 + ... = Suffering
In the classic Buddhist disciplines, one eliminates desire (whether as an end goal or upaya is up to you to decide, or more appropriately, ignore). To phrase it again as math, it's the trivial solution to the equation above:
0 * d1 + 0 * d2 + ... = No Suffering
My hypothesis is that the coefficients need not be 0 to find a non-suffering answer.
(And, in fact, I do believe that's what Buddhism teaches, or shows, eventually. But all of the above holds.)
As a practicing Buddhist for a decade, having attending multiple retreats including a 30-day one, this statement right here indicates the flaw in your argument:
In the classic Buddhist disciplines, one eliminates desire
Actually, Buddhism is about being OK with the desire, but the idea isn't to become some robotic zombie walking around. That's a classic mistake. Buddhism DOES talk about the ability to first limit and later eliminate your REACTIONS to desires, but never the desires themselves. They will always arise, no matter whether you're enlightened or not. It's a question of whether you respond to those arisings.
Agreed that there can be other solutions as well. However I do think Buddhism has some very valid critiques of unity and duality that it's well worth paying attention to.
You can throw away expectations about how things are, without stopping work on making things better. Anger is not useful without action.
For instance, I know someone who is very giving with his time and energy, but when someone fails to thank him to a degree that he thinks is proper, he gets really angry about it.
I've tried telling him not to do things with an expectation of something in return, even a 'Thank you', because it will just make him angry. He should be doing them because he wants to do them for the person.
For another example, a lady gave to charity at work every year. Then, her daughter fell on hard times and there wasn't enough money for her daughter, and her grand-daughter. She went to some of the very same organizations that she donated to for years and they all told her that she wasn't their target and they couldn't help her. She got really angry and stopped giving to charity at all.
I don't blame her, but she'd have been much less angry if she'd not expected anything.
Rather than letting go of all expectation, simply shift your expectations as required by reality, and shift them without anger or regret. If one of your predicted expectations goes wrong, use Bayes' Theorem to adjust your probability functions until your expectations are right. If expectations turn out to be unpredictable, then we might wish to not have them. I don't think that is the case.
Here's more from the Tao Te Ching:
The Master's power is like this.
He lets all things come and go
effortlessly, without desire.
He never expects results;
thus he is never disappointed.
He is never disappointed;
thus his spirit never grows old.
The other concept indicated in the last paragraph on "results tank" not "effort tank" is lust of result. There aren't as many sources discussing this topic directly, but Zen in the Art of Archery  is good, as is Watts' Way of Zen .
I highly recommend them all for anyone interested in creating things.
The fact that some expectations don't match reality does not imply that there aren't any expectations that match reality.
Realistic expectations seem quite reasonable and useful.
Note that realistic doesn't have anything to do with your preferences.
My friends and family often tell me that I'd be more content if I lowered my self-expectations, but I have trouble not equating that with throwing in the towel.
Is it possible to obtain a healthy balance in the middle? I hope so, otherwise I worry that the next Benjamin Franklin, or Steve Jobs, or insert-your-favorite-overachiever-here will read advice like this and take the easy route instead of working harder to follow their dreams.
Seriously though, I'd be thrilled if anybody could suggest that both are somehow possible.
But even if I act and prepare myself to cope with people doing unexpected stuff, deep down I'm still hit when they actually do it. And this deep feeling is hard to suppress.
Besides, if you want to actually do something with other people, you're bound to make some assumptions on how they will react. Thus, expectations.
Some expectations are a good thing. Just let go of the bad ones, or learn how to let go if an expectation is not met. You don't have to get upset when expectations are not met.
Zen is all about cutting out the BS in your mind. Living inside your dreams about what should be, what should happen and what should have happened is all bad thinking. It's illogical.
Zen helps become less wrong.
But it falls apart when you mix in other people. Because, if other people are emotionally immature (and most people are) they'll perceive you as weak, and limit your opportunities because you're not posturing as a chest-thumping blowhard. Thus, you too have to speak the language of power while knowing full well that you don't buy into it. I can think of nothing more boring than taking yourself seriously.