As people play/talk with others, they learns things about the other person. When one person does something dumb or they disagree on something, they might become enemies. From that point, they take it on /ab/ (which is ALWAYS a mistake to do) most of the time which just makes it even worse.
Many people start shit because they want to call the other person/group out, inform people about stuff they shouldn't know about, or just because they're bored as shit. It's what happens when people know too much about others.
That and the fact that there's been a lack of influx of new members, so we're forced to either go to other communities to meet new people, or talk to the same person.