Noob here, from my perspective it’s been pretty welcoming and friendly, but I’ve got to say it does feel like everyone’s known each other forever and it’s hard to break into a conversation when you’re not one of the old regulars. That’s obviously going to happen if you join a forum where people have been getting to know each other online and in person for years, and I definitely don’t think the in-jokes and gentle piss-taking should be toned down just to cater to new people like me, but I think that’s why there might not be so many new people posting. It can be intimidating trying to join in a conversation when everyone’s already pals, and even more so when there’s about three or four threads active that just contain old members saying how great they think other old members are.
I agree that some people might get put off when they see someone else describe stuff they like as being shit or boring, and while that might be one person’s opinion or a joke, or even an in-joke that predates these new boards, if you really like a band and see them getting habitually slated by everyone else then it feels like you probably don’t belong here.