While I won't speculate whether Gavin is Satoshi or not, it does seem to me like it's more likely that Satoshi would continue participating in bitcoin under a different name rather than quitting altogether. It's hard to stay away from online communities that you're invested in, but one might want to push the "reset" button on their reputation, which is something the internet uniquely allows one to do. I believe it's plausible that Satoshi's beliefs in decentralization and consensus caused him to shelve the BDFL mantle so that his ideas could compete on their own merits.
