I think that its a natural social occurance for cliquey groups to form. Anyone who has been watching Celebrity BB () will have seen this first hand. Its natural for people to be drawn to people with similar ideas or views.
Any kind of forum will have its regular posters ( ) who spend a lost of time there. The level of cliquey-ness should, IMO, be measured at the willingness to accept new people into the group. Not once have I seen anybody flame a newbie on here. We usually welcome all newbies with open arms.
What makes this forum less cliquey than others is that you can ask totally dumb questions and it'll get answered (usually) without much teasing.
As all members here are of an equal standing its hard for an us and them situation to arise, which IMO is good for the site
Thats my 2p.....