Our British justice system is based on rehabilitation as we are not killing criminals or sending them to Oz any more. RMS has not actually committed a crime that I know of. Whether actions deserve a life ban will depend on various factors and it is up to those with the power to impose it. From what I have heard about RMS he lacks some social skills and may not filter what he says. We know the free software world has others like this, but they may be good at what they do. FSF have to weigh up whether his presence is good for them.
I do think 'political correctness' (horrible term) can go too far, but those who say offensive things can expect to be called out.
RE: RMS is back, back again