Most of my time lately has gone to the absurdity that is the start of the semester, when teachers are frantic to put a dent in the syllabus, students (especially the icoming fall freshmen) have no idea what they're doing and do silly things like run around in absolute panic and turn the parking lots into a demolition derby. That sort of lovely thing.
But normally I am available for RP, and shall be again once I'm a couple weeks into this thing and people realize it's really not that freakin' bad.
In the few instances where I have personally turned down RP, it was because of time issues. In the one instance I have seen someone ask to be included in a scene and denied, it was because it was an already-large scene (which some of the players commented on sizewise) for a specific pack to do an important pack-related thing, and scene size + you're not pack = not this time, maybe next time!
Which I don't think is being cliquish, so much as it is practical. Which is another point: Just because someone wants into something, and does not get in it, that does not automatically a clique make. There could be legit reasons.