Good overall, but ending was a bit disappointing.... (spoilers)

Humans and dragons being capable of living together was the theme from the beginning, but in the end, humans, including Hiccup's people are not worthy? Given how close and easy it seemed to travel from the Hidden World to the new island, I thought the dragons should have all moved there for protection, but came back all the time for visits. Obviously some of the dragons in the outside world had been there before, including the Light Fury. Seemed very disappointing that like 10 years pass before Hiccup and Astrid see their dragons. Doesn't seem to be much of a reason for it.