Maybe I'm reading this story differently, but I never saw Troy and Miles simply as the "good guy" and the "bad guy." From the beginning - as the title itself says, ...the Long Road Home - for me, this was a story of a journey.
And though I understand readers' disappointment with Miles and his leaving Troy, it was never something as ugly as cheating that would make me see him as the irredeemable villain of the story. Miles' childhood was so much different than Troy's; although Troy had his own share of pain and trauma with his twin, he was surrounded by a supportive and accepting family.
If we look at the years Miles spent on the boat, what do we see? A boy alone with his mother - and that makes the relationship between Miles and Robbie so touching, as it reflects Miles finally getting to claim the precious time with a mother that he never had.
There is a clear contrast between Miles' and Troy's chapters. As much as I enjoy Miles' journey and the adventures of a boy, it's obvious that Troy has grown up. He has become a man. His life, much like reality, lacks grand adventures, but it confronts us with the very real problems that come with maturity.
So, they are on different roads and at different stages of growing up. If the possibility of renewing their relationship ever occurs, it won't just be because of Miles' apologies; it will be because their lives and minds have finally reached the same page.