User blog comment:Dual Energon/What I think makes HTTYD 2 the supremely better movie./@comment-26703272-20151115084809/@comment-24865409-20151116104712

Yes, there is that 1% chance, but in the show the tribe has multiple moments where they turn their backs on Hiccup again and again, yet at the end of the episode he is still unfazed by it.

In the books Hiccup does ask himself at least once "Why do I help these bastards?". He doesn't say exactly that in the books but he does question their worth after multiple instances of them reverting to their old ways.