I quite agree with Galadriel55.
If we are supposed by Tolkien to imagine that Eru is secretly guiding Túrin’s fate in this matter, then you presumably also imagine that Túrin being the only, or almost the only, survivor from Nargothrond is due to Túrin being helped by Eru, even though the Elves of Narogothrond are not portrayed as at all evil folk.
But then I suppose you do not imagine that Túrin’s marriage to Níniel, not recognizing that she was really his sister, was also Eru’s doing?
That Túrin “seems to be the only one of the outlaws of his group who honestly felt remorse for what they’d done″ is nowhere said in the tale. Indeed it is specifically indicated that Aldgund the Old did feel remorse. That the majority of the band agreed to take Túrin as their captain when he planned to lead them away from the Homes of Men, saying, “at the least we shall earn less hatred of our own kind,” shows that more than one felt that way. Later when Andróg urged the outlaws to slay Beleg, “some of better heart” spoke against Andróg even though the missing Túrin had made Andróg the leader of the band until Túrin returned.
If Tolkien had written a namby-pamby world in which the “good guys” always won, his work would hardly be so popular.
As Tolkien writes in
The Letters of J. R. R. Tolkien, letter 17:
One reader wants fuller details about Gandalf and the Necromancer. But that is too dark – much too much for Richard Hughes’ snag. I am afraid that snag appears in everything; though actually the presence (even if only on the borders) of the terrible is, I believe, what gives this imagined world its verisimilitude. A safe fairy-land is untrue to all worlds.
Tolkien wrote the “Story of Beren and Tinúviel″ which was a romance with an ultimately happy ending. Then he wrote of Túrin which had a sad ending, most of which was not really Túrin’s fault, although Túrin has his flaws.