Yeah especially with barbs on. AI has trouble clearing barb camps on islands.
But even without barbs, the AI just does not like to settle on islands. It would be nice if they could have changed that coding for Indonesia. On the Greatest Earth map (YAMP mod) they do like to settle on New Guinea with barbarians turned off. The AI loves that island. I often see the Aztecs settle it, sometimes Japan or Australia. But they won't settle any other islands. Instead they go to unappealing locations in Africa or Siberia.
My last game on fractal actually had the best performance of Indonesia. Interestingly enough, they seem to do better with a pretty sizable chunk of land, at least as an AI. That game had about 7 or 8 Indonesian cities.