People have been gathering in Ul'dah for several reasons:

1) It has the most convenient layout
2) All the cities' storylines eventually meet up there
3) For a long time early in the game's life it had the best high level levequests
4) Due to all 3 of the above, everyone set their retainers to sell items in Ul'dah's Markets, and because of that it's the only place you will find players selling things.

It's fine to hang around in whatever city you like now that we have airships, but if you want to socialize you'd want to head there. As was mentioned /shout that you are looking for a LS will help, or you can try your server's forums on this site.