First off, I think that the depth of Gollum's 'addiction' to the Ring shows just how sinister an object it was, that it could totally ensnare someone. What happened to Gollum says more to me about
The Ring than it does about Gollum and his personality or predisposition to evil or not. Especially when set against what happened to Frodo and how he failed to do the deed of throwing the Ring away and how broken he was.
But anyway. I agree that many (maybe even the majority) of Men would have believed on a most basic level that wrongdoers should get their 'deserts'. In the real world if you do polls on if people agree with things like capital punishment the majority always says 'yes' but it still remains firmly off the statute books; that's because we give over the making of serious decisions of that level to law makers and experts, who we expect to act in a level-headed way. You do not expect a lawyer's decisions to be swayed by things that have happened in his or her personal life - they are expected to be professional in making all decisions, to simply weigh up evidence dispassionately. That also holds for Middle-earth. An ordinary Gondorian might think a criminal who knicks his armour deserves a good kicking, but the rulers of Gondor would say otherwise - they are there to take a professional overview.
I hope that makes sense.
