half the people will end up not doing what they want.

You don't want family traveling all the way to paradise and almost getting to snorkel/see historic sites/explore nature/shop/etc. You can't do it all together and don't try.

There is plenty of time on the ship to eat together, swim, attend shows, chill. Those who similar excursions can take them together and then everyone has fun telling the others about the adventures they had.