Second: Criticism is not always 'angry'
Third: Consider dealing with the crass criticism as a life lesson.
Fourth: Mindless praise is not going to help you grow
Fifth: How you present something will often determine the type of response you get.
You are going to leave kindergarten some day, the world isn't all gold stars. You are going to have to deal with people giving a critical analysis of what you're doing. That is what will make you better, not endless back-patting.
A. "The world isn't all gold stars" (a.k.a. "it's a dog-eat-dog world out there", or "there are a lot of hardasses out there", etc.), THEREFORE
B. I'm personally not going to pull any punches for this naive/hopeful/idealistic/etc. young person.
This isn't logic; it's a weak rationalization for being an asshole, because there's a certain pleasure to being an asshole and cutting others down to size.
Is there really just a black/white choice between "crass criticism" and "mindless praise"?
Of course not. What about this: filter whatever critique you have to offer down to what's useful to a 14 year old (or whatever they are), and present it with kindness.
As an example, there was one section of organic chemistry for freshmen, and to get into that class you had to have a 5 in AP chem and pass two exams. I saw many of my classmates (Columbia) who were genuinely taken aback that they weren't the top of the freshman class -- and many of these self-styled rock stars never heard of the IChO!
It is better for long term growth if kids are humbled at an earlier age than to be shocked much later in life. And holding back criticisms now really does a disservice later in life.
> It is better for long term growth if kids are humbled at an earlier age
You don't humble a kid. That's not an action any person needs to take, ever. Instead, you expose them to the wonderful things in the world, and they will learn humility and be inspired and motivated at the same time.
If you "humble" them instead, they may learn humility, at the same time as they learn how shitty some adults are, and you seriously fuck with their motivation and inspiration.
I'm aware this may not be quite what you meant; maybe I'm reading too much into your wording.
But while I agree that false praise is bad ("kids are told they are prodigies"), the solution isn't to cut them down; it's to show them more of what's possible (and of course, replace the false praise with simple recognition of how their hard work is paying off, noticing improvement, etc.).
You want to build a drive for self-improvement in them; not convince them they're already at the pinnacle (as if anyone ever is...), nor convince them that they're currently worthless compared to the best (because it's not a competition) -- just notice how they're getting better at climbing, show how it's making their skills/lives/etc. better, and help them along.
> And holding back criticisms now really does a disservice later in life.
Holding back criticism isn't the problem; their limited understanding of the world is. Once you name the problem, the best solutions look quite different; there's no need to tell them their work is low-to-mediocre; they'll be saying it themselves (but with a drive to improve).
There are also still people who will be nasty to kids with the idea of "toughening them up"; this is crap as well (kids can better deal with shitty behavior if they have a solid idea of what is non shitty behavior, and if they haven't been traumatized into having intense emotional responses in conflict), but I don't have time to get into that in depth here....
So, when you talk about criticism in a general way, you are missing the point. No one is suggesting we coddle anyone. We should however remain professional, which is the problem some people are having.
Unless you are saying that we should encourage all criticism, even bad criticism?
I think the age matters to give appropriate advice and direction. With the case of the 14 year old, they don't have the life experiences to be able to get certain analogies, and they have a different set of opportunities available to them. At 14, you can prep differently, you can go to college for computer science. For the 40 year old weekend hobbiest, going back to college is generally not an option, so the path they have to take to get proficient is definitely different than the options the 14 year old has.
No-one is expecting you to give out gold stars.