What happened to the Dark Island?

While the area was cursed by the Overlord, he has long left that place since. There seems to be nothing bad about the environment(I know the area with the Celestial Clock was pretty dark but it looks normal in other scenes) and it actually looks quite lush in the Dark Island Trilogy. I am surprised there has been no attempt of any colonization there after it's discovery, and the fact that it has been untouched EVEN after the merge is shocking in my opinion Although it would make sense a...