Just as some others, I sometimes think an age-restricted section would be a good idea, with 1 rule, don't get personal, with the thing being if you do get personal about people, you're simply not allowed to view or post in there. And as much of a good idea I think that may be, it wouldn't necessarily keep the normal, publicly viewed chit-chat section free from childish and bitchy behaviour. I used to frequent a bike forum, and amongst it sections was 1 called something like, 'at the bar' which was over 18's only, and had no rules, but the normal boards were the worst of any forum I've ever been on. Every single thread, within 2 pages turned into an argument and mass of personal attacks and threats.
So while on occasion the moderating can seem excessive (and I do agree there are times when I really wonder why something has been moderated) but simply giving a section to allow people to go silly won't necessarily clean up other sections.
PS, the thing most annoying to me about chit-chat, is that threads aren't allowed to wind on and evolve into different things, you must stick to the original topic. Some of the best threads on other forums are the 1's that go on for hundreds (I think theres 1 that's now been going for around 2800) pages, because the topic changes and it's more like a conversation than 1 single subject, it's when you really get to know people and feel like you know them when you finally meet in the real world.