Boards are like bars; there are different expectations of social propriety from one to the other. My eyes don't see a correlation between polite and popular. Take Enworld .. please.
Really, take Enworld as an example. It's not a place that is particularly polite, but it is wildly popular.
Around here, there's a serious focus on development, and that means work. This is not the emphasis of most boards. Sure, all these other boards talk about gaming, but none of them do anything about it. Okay, that's a joke folks, don't get your panties in a wad. Really though, not everyone here is focused on work for print; maybe they're just working on their own home game, but many, if not most folks, are doing gaming work. That's a greater commitment than just chatting about gaming, and so maybe the volume and traffic will then necessarily be lower here.
K&KA is the place to go for Talmudic level discussion of AD&D. Of course, it's practiced as a full contact sport, and it doesn't hurt if, at times, your pads are made of asbestos. To me, K&KA is The Dungeon
, and I'll act accordingly. Don't poo poo the idea of hanging out in a place where you can really let your hair down. Sure it gets out of hand at times, but there are bouncers (mods) to take care of the worst of it. K&KA also seems to be self correcting, if you stick around long enough to catch that.
S&W is more like The Sazerac
. A nice place where you can talk at a low to moderate level (polite if you will) and conduct business.
Me? I'll be snarky in any establishment. I only change the volume accordingly.