[narfforc]

Remembering that after all, these are stories from the mind of a man, we must accept the flaws. Tolkien uses many myths as blue-prints for his own sub-creation,
so we see there is no point in Utopia without corruption, but then where the main criticism of Tolkien comes in, is his lack of Hell without redemption. There are lots of good gone bad elements, but where are the bad redeemed. The only two instances in LotR are:

Boromir is corrupted by the Ring (briefly)/ He redeems himself by trying to save Merry and Pippin

Smeagol (good?) corrupted by the Ring and kills Deagol/ He almost turns ,until the nasty words of Sam(un)wise Gamgee on the Stairs of Cirith Ungol, and the fleeting moment has gone.

So why are there no bad turning good, Why doesn't Saruman come down (pride),
why doesn't Grima repent (fear/hate maybe self-loathing) Ted Sandyman becomes a collaberater, what happens to him. The whole point of the story is Good battling Evil, you cannot allow your evil to turn good, for evil will always defeat itself , and in Lotr, Good allows Evil to do this.