First, that it has good protection from the elements. It has, for a recreational sailor, probably good facilities so I can go and shower. Next is probably that I can get some good provisions nearby. Third is probably that it has a couple of nice restaurants and maybe a good bookstore I can go to.
Kingston is a good example of a good destination because it has many amenities. To me, it has become too noisy, and I don't go there that often.