Fair enough. Were I in his position I'd likely feel uncomfortable with the public persona that had grown around me and the expectations of the geek community.
He received a lot of flak for settling with Sony when many of his supporters expected him to "fight the man"--and win. It was likely a smart decision for him personally. That said, he took donations from people who expected that those donations would be used to defend our right to pull apart anything we buy. I guess the disappointment in geohot comes from seeing someone (rightly or wrongly) who championed the values that a lot of us hold weaselling his way out of the fight. Joining facebook is a fairly ignominious end to that tale.
Maybe he didn't want the publicity, maybe he didn't want to be an activist, and maybe he resented the expectations that were placed on him. We (the geek community) had expectations of geohot, not George Hotz. It was the character, not the man, that we liked. Maybe he was just tired of playing that role.