The thing I think will be most interesting to understand in retrospect is how much of a filter the SO community has been in terms of blocking and shaping the generation of programmers who've started out since it has become the go-to site for help.
University degrees act as a filter to a certain extent. And many fields have courses at the beginning that are designed to weed out people who are not going to be successful in later coursework. And the result of that filter is a certain homogeneity people that make it through that filter and become successful.
The internet has done a really fascinating end-run around the university filter, and has been described as an an equalizing mechanism in society. But filters and enforced similarities are things that spontaneously emerge from societies--even anonymous ones on the internet.
While it's true that SO doesn't claim to be a learning resource for beginners, most google searches lead there, and that's a real part of its function no matter how much the managers claim it shouldn't be. And the response that beginners get is clear: conform or get out.
I think the social tide in the work place is moving against that kind of attitude. Developers are no longer quite the magical group of secretive wizards that they used to be, and the sort of Linus-style kind of treatment of people who aren't completely on it isn't really tenable in business situations anymore. A lot of the jobs that I want to apply for are more and more frequently focusing on being a good colleague, not just a good programmer.
I think SO has two obvious directions it can take. The first is to allow the core contributors to continue to lay down the law and remain, shall we say, aloof and concerned primarily with maintaining their fiefdoms while gradually shrinking in relevance and contributions. And the other is to, well, not basically.
I don't think either one of those is actively bad. There is value in maintaining the strict order that SO does. But that value comes at a cost. There's a high barrier to entry right now for being an influencer on SO, and that's good if you want to remain the authoritative place to find good answers. It's bad if you want a next generation of leaders to come in and replace the ones who are currently at the top when they wander off to do other things.
I remember reading a story about what happens when you listen too much to how people use your product, and the example case was Excel. It was supposed to be a spreadsheet. But Microsoft--ever the leader at market research--figured out very quickly that people were using it for almost everything but spreading sheets! And Microsoft--also the leader at getting product decisions massively wrong--decided to make Excel do pretty much everything instead of developing a separate product to fill those use cases. And now we're at a point where Excel does basically everything, and getting people to not fucking use it for everything is almost impossible.
So yeah. They need to keep a tight focus.
An interesting counterexample is EvE online. For almost 2 decades now, the games has had a reputation for being hardcore, elite pvp. The weak need not apply. Piracy, scamming . . . being the bad guy in every way is not only allowed, it's encouraged. That community filters itself very effectively. Whining about what's fair or not just makes you more of a target. People farm new player tears as much as they farm space dollars. And it shows. CCP Games has had a tremendously difficult time staying relevant in the MMORPG world and in the last couple of years has been forced to make sudden changes that really disrupted the existing community in an effort to appeal to new players. Nobody really wins there.
It will be interesting to see what happens in the next decade. It's a legitimately difficult management challenge, and I'm not convinced that it's possible to avoid what seems to be the inevitable rise and decline cycle of all social networks.