Why is the 20 year period before the present off limits for discussion? Is it too controversial?
What follows is a hypothesis I made from seeing 22 years of history unfold around me, and which was aided with tools that I learned from a wise history teacher.
Being a historian of the present, I think, is a potentially dangerous occupation. And it has been for all of presently surviving (as of this writing) history.
History is something that wars are fought over. History is written by the victors of these wars, and the opinions of the defeated are forgotten. Wars are a battle over the psychological state of the population, including their collective memory. Present history is thus an area of strong contention, usually murderously strong contention, contention at a level that many people are willing to die for.
However, once enough time has passed, the cares of the present will have migrated far enough away from the cares of their younger selves and of their ancestors such that those past concerns are no longer objects of murderously strong contention.
My writing style is a bit dense. I apologize if this was hard to read.
Edit:
I originally came to /r/AskHistorians to ask about the history of Reddit, to ask about any historians who study Reddit, but I was unable to find justification for this type of question in the rules, hence the question at the top of this post.
The reasons for the rule are discussed in this thread.
In general, there are 3 reasons that the subreddit does not deal with such events:
People start thinking their personal experience of events matters historically, which it doesn't and which breaks another rule.
Politics and recent history are strongly intertwined, and this subreddit is not about discussion of politics.
Historical detachment is difficult, if not impossible, for recent events.
A recent meta thread should hopefully provide all the rationale you need for this particular rule.