I wish it were so, but though I hate to be cynical, this has been going on (for me) since the early 90's (back then Microsoft was the one everyone connected to) so I doubt that anything is going to change.
Maybe it needs to get worse before the tipping point is reached though and API developers start genuinely caring for the wellbeing of their developers and acting with a greater deal of integrity and empathy.
Established businesses should feel less secure today as it seems far harder for one business to have a stranglehold on the market. Software distribution costs have been lowered by the internet. Development costs have also been lowered because we no need to push wheelbarrows of cash to Oracle, et al. We have better tools, better infrastructure, and shorter development cycles. Marketing is easier, cheaper, and more apt to give rapid feedback.
Network effects are still horrible barriers to overcome on social networks or phone platforms. Once a company has large numbers of active users they tend to win, and once they start winning they have little incentive to care about the well being of individual third party developers. Once they have the eyeballs the third party developers want access to, they can treat most of them like dirt, and they can still count on more lining up to use their API.
If a company like Google struggles to launch a new social network with their existing huge user base, you know its hard. Yes social networks and platforms do die, like MySpace and RIMM, and new ones burst in to prominence like Pinterest or Android, but for every new network or platform that succeeds, hundreds or more probably thousands fail.
Small third party developers have strong incentives to put up with the risks involved in using API's provided by dangerous companies like Twitter, Facebook and Apple because they have to if they want to get access to all the users those companies own.
We see turnover all the time. The network effect is interesting, but creative people can and do overcome it. reddit overcame it by faking user activity until they actually had a community. Facebook overtook MySpace with exclusivity combined with an exponential rollout. LiveJournal lived and died because of its community and the "network effect"; Tumblr has now achieved what LiveJournal had only dreamed about. The network effect is a difficult hurdle to overcome, but the best do and as a result we end up with a "new internet" ever 5-10 years or so. Craigslist might be the next giant to lose their golden star, and I wouldn't be especially surprised if they do.
Google failed in part because they never really communicated what Google+ is. I still don't really grok what it's for or why I should use it, and that's why I don't. They really just didn't produce a compelling product, brand it well, or market it effectively. For whatever reason, Google's marketers doesn't appear to be of the same caliber as their engineers.
Someone will pull Twitter's pants down and at the same time eat their lunch. I love Twitter, but I can't wait to see what cool thing replaces them.
"I still don't really grok what it's for or why I should use it, and that's why"
Uh, its for pretty much the same thing Facebook is for, except you can do lists and make them public or private, you seriously didn't get that?
Or did you just not use it because the people in your network weren't using it. If your friends are already on Facebook there is almost no reason for you to migrate to a new social network where your friends, or chosen thought leaders, aren't active. Maybe you will tack it on as a 3rd, 4th or 5th social network where it will mostly just consume more of your time.
As I said, yes network do rise and fall but it is enormously difficult to get that ball rolling and keep it rolling. FriendFeed was an awesome social network, with all star founders, but it never gained that critical mass, the founders gave up believing they could displace Facebook so they sold it down the river... to Facebook.
Don't count Google out yet. Just because it hasn't become hugely successful in it's first year doesn't mean it won't. How many users did Facebook have in 2005? Twitter in 2007? Google has put enormous resources behind Google+, and they don't show any sign of backing down. They're taking dozens of separate services that they provide and integrating them through Google+. In 5 years, that's going to be a very compelling platform.