If you go to boards with large forums on all sorts of topics, pets and health issues just being 2 of types, almost all of them have a room for threads which are off of the main topic. Some even have multiple rooms which don't relate to the main topic of the webpage. Even if there are not huge amounts of posts on some of the IMO topics, they do get read alot. And even in the Lounge, there are a lot of discussions, such as ones on dating or job situations which are not related to cats at all, other than as it relates to the bucks to buy their kibble!
If you were to sign up for the NY Times online, which is free, but requires registration, and checked out their forums, you would find that our discussions are quite civil in comparison. Most of the posters there are as civil as we are, but there are a few in each forum who delight in baiting each other, and quite strenuously.
Plus, these VBs software boards allow you to click on a poster's name and 'ignore' them, if you don't like their posts. You won't see their posts when you go the forum, unless someone quotes them. You just see a note that so and so has posted and they are on your ignore list.(You also always have the option to read a post from someone you have blocked by clicking on something in their message box.) I don't block anyone here, but I do block a few users on a health related forum who 'dismiss' modern medical theory to a degree that I find so stupid/annoying that I prefer to not read them so my blood pressure doesn't spike. (I'm talking abt things like advising people that you don't really need sun block at all in the summer, or discussions of high colonics or telling people that medications they NEED to take for another problem like high blood pressure could make their other problem worse, so they should stop taking the bp meds etc.) If someone's opinion on a specific topic comes up frequently, and it upsets or bothers you, block them.
I actually think that focus of the IMO forum should be expanded to include other topics which are not contentious, but are not cat related, or general chit-chat or dishing abt diets, dating, jobs etc, like when some tragedy or event occurs and people want to talk about it.