Could you elaborate on 'old guard' and 'switchover'? Wikipedos all used to be as spastic as Ryulong?
That's a tough question. I think of Ryulong as someone who has continuously been on Wikipedia since the fairly early days, and has gone through and adapted to a few different periods on Wikipedia. So... this post is turning into an essay on Wikipedia history, but since it's focused on explaining the concatenation of circumstances that led to Ryulong being crazy, I'm gonna go ahead with it.
I'd carve Wikipedia up into three major time periods. The early days, the politicization of Wikipedia (i.e., making it policy-based, not making it political), and the ongoing professionalization of the site.
The early days, I'd say fall sometime before 2006, maybe before 2005. The admin bit flowed like cheap wine. I saw old successful RfAs from that period with ten "why not" supports and no opposes (said person still has his admin status, though came damn close to losing it last year). Those people tend to be a mixed bag. I met one at a Wikimedia conference last year who was a delightful, if eccentric, young woman. This group also includes a lot of curmudgeonly, trollish types, many of whom were driven out or just moved on. But by and large these folks are harmless, usually real knowledge lovers, and generally very technically savvy people.
The politicization of Wikipedia, I'd say falls after the early days, around where Wikipedia started to get a
LOT of media attention, and when use of it as a vehicle for promotional activity grew exponentially. It was the heyday of random vandalism, but before edit filtering and effective automated vandal fighting techniques. Processes and procedures abounded. RfA and AfD were two places that became really complex and acerbic in this period. A lot of older folks didn't keep up and either retired or got pushed off when they broke some new rule (or new interpretation of an old rule). One of the big deals here was that, because the encyclopedia grew so much, walled gardens started to disappear.
The period we're in now, and where all the on-wiki GamerGate insanity comes from, I would call a period of professionalization. Wikipedia is big and they know it. Media reports of on-wiki conflicts and mistakes from the prior period (some of which are significant enough to have Wikipedia articles written about them) have put the fear of God into the Foundation and the hangers-on. As a result, people are becoming hypersensitive to reporting things that could upset article subjects. I'd say the Manning ArbCom case represented the final movement away from the previous period. The controversy over Eric Corbett and civility is another defining matter of this period. So, people are expected to behave as professionals in the public eye.
Now, what the hell is Ryulong? I would say he's someone who mentally belongs in the group of people from the early days: Savvy about minutiae and particular about his own way of thinking. He adapted to the period of politicization decently well, and generally knew where the axe of policy would fall, but ran afoul of it from time to time (presumably from his ties to the first group). Finally, as Wikipedia attempted to move away from a policy body to a professional body, Ryulong just couldn't adapt. You can't just bean people over the head with policy in quite the same way that you could in, say, 2009.
As for other old editors? I don't really know many. I feel like those that are successful managed to keep their walled gardens, and thereby avoid the conflicts that Ryulong stuck to: One guy I met, who has something like the #3 edit count, does nothing but categories. Others professionalized their own lives (some of the people who run the Wikimedia DC chapter, for instance). These folks are all pretty weird, but have not had the dramatic, public downfall that Ryulong had.
