I'm going to try to make this a well-thought-out post but it's been a long day and I'm preggers so you'll have to bear with me a sec.
I've been a member of numerous forums for around 10-12 years now. There have been a few where, years after I left, I thought I'd go back and look at some of my old posts, and I was REALLY horrified at my attitude in a lot of them. I'd thought of myself as having all these great points to make, and I was all ready to debate them out with people. Usually I was put in my place pretty quickly but I definitely noticed a tone that, thankfully, I've grown out of. I get along with more people now; I am less likely to jump down someone's throat for disagreeing; I've become a bit more well-versed in what kind of humor to use at what time. In short, I've become much more skilled at figuring out how different social settings work. I'm still not perfect of course, but I'll settle for "better".
As far as the forums themselves, the general makeup of each community was often very different, and of course each forum was handled differently by the mods and owners. Some were much more tolerant than others, and some were extremely strict. Some lasted for many years, others died off after just a short period of time. I don't think there was any correlation there though.
Now, this brings me to several points. First of all, people are sometimes going to be idiots when they join a forum. This may be because they're young, or because they're used to a different subculture, or because they think they're being funny but it comes off as crass, or... you name it. This doesn't mean they're going to suck forever as a forumite. It does mean they're going to need some direction; and in some cases that direction may just be "exit stage right" but not always. Some people are more pliable than others but are just having a hard time trying to fit in. Many are probably trying SO hard, in fact, that they're just making themselves look bad. It doesn't make them bad, just misguided.
HAVING SAID THAT, and this is really my main point: This is truly a Private Forum. It is owned by someone who has opened it as a privilege for those who choose to visit his site. It's not a game FAQ forum, or a software support forum, or anything else that is generally "expected" to be offered. Because it's not run by a company who has a PR rep that says things need to be a certain way, it means that Jeph himself gets to decide what is or isn't acceptable on here. If he decides one day that everyone has to include a picture of a giraffe with each of their posts, and gets ticked off when people don't, it's his prerogative. If he says "talking about my characters like that is creepy and I really don't want you doing it" you should absolutely respect that. If you met him, would you start telling him about a fantasy you have about one of his characters? Of course not, because you know he would be upset. So why is there an outcry about it on what is essentially HIS forum?
I know this is rehashing what's been said before - "forums are a privilege, not a right" - but from what I've been reading it sounds like a lot of people here have forgotten that. If someone tells you "please don't do that here" just say "fine" and move on. You'll live. You'll be alright. You may even realize years down the road that you were kinda being an asshat anyway. And if you still truly think you weren't, then maybe this isn't the forum for you.
tl;dr:
1. Some people come across as asshats because they aren't used to the "flavor" of a new forum. Often they don't mean to be. If they DO mean to be, boot 'em. Don't let them poison the forum and sow frustration.
2. Don't be an asshat. If someone tells you that you are, don't say "But but but" say "Oh crap, I didn't realize I was being an asshat." Learn from the experience.
I'm pretty much brand-new here and mostly just lurk, so please take this for what it is - just my POV, not "This is how I think you should do it." This is not the first time I've seen a discussion like this