> My guess is he secretly wishes he had chosen a different, non-copyleft license.

He always wanted a copyleft license because it enabled kernel development to really take off by enabling him to make use of other people's contributions, and he's always been consistent about that.

I bet that what he really regrets, though, is not requiring copyright assignment for inclusion into mainline, so rogue developers can't just join up with the SFC and sue people against his wishes.