I think I can explain some of it, having experianced alot of it. Anime, specificly gundam, is where alot of people get started, it seems to evolve from gundam to scale for those with the tallent, its how I was.
When you have forums specificly for sci fi, you tend to get alot of the same questions asked thoulsands of times over, basic questions. It gets people frustrated, and they take it out on others. I have seen a few forums completly die out, and some on the verge of dieing because of this thing. Also overzealous moderators seems to gravitate toward those forums. I had an account deleted and my IP banned from a site because I called one of the members a Nazi (a 'Chat Nazi' in the way of sienfeld's 'Soup Nazi') because of him saying things about profanity and such in the chat for the forum, even though we all were adults there, and such.
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I just read and saw what you mean. I posted a little reply, I know people like that, theres only one way to deal with them, and its to get rid of them.