It's difficult to comment on such a vague statement. You haven't really provided any details of the time you spent on Catskills, which chats you're referring to, or the efforts you made. For a new player on Catskills, I would suggest not only relying upon the general chat, but also posting here on Stratics. You're bound to get a lot of responses and offers of help. And I don't really know about any Siege specific prejudice existing here.
On another note, and this isn't directed at you in particular, VinnySP, I'm tired of posts that perpetuate this myth that Catskills is not a welcoming place. I've only really ever played on Catskills and Atlantic, and while there are things I like and don't like about both shards, I never felt that either of those places were so incredibly difficult to penetrate as a player. Because UO's population has dwindled so much over the years, players have become this resource and there's been this dramatic shift so that the burden seems to be on the shard to make someone feel welcome, rather than the new player to put any real time or effort into finding their place. For as many stories I hear about people not feeling welcome, I have just as many stories about people being given a ton of attention and equipment and effort and still vanishing anyway. Ask any GM of any particular play-style and I'm sure they'll know exactly what I'm talking about. It's frustrating as hell.
People also forget that as players, we're not being paid to be a welcoming committee. All of us have jobs or lives, and for the most part, play this game to be entertained. I don't mind devoting a certain amount of time every week to helping new people or answering questions, but I also need to be able to play UO for myself. Similarly, it's OKAY for people to favor specific play-styles or interests in the game. The word clique is always thrown around, except I would argue that people are entitled to focus on a particular play-style with those who share it. That's why we have guilds to begin with. As a role-player, I shouldn't be expected to be interested in certain things, just like I don't expect everyone to enjoy role-playing.
But all in all, I think that Catskills is a very welcoming place and that if people put in a reasonable amount of time and effort, they will find a place here for them. It's a good shard and I hate hearing anything that presents the opposite image.