I've been on 7 cruises, all but one stopped in St. Thomas, and we've not big shoppers. The first 2 times we got off the ship as soon as it docked in St. Thomas, the next 3 times the St.Thomas day was the day to sleep in and get off the ship at our leisure. Of course, with current immigration laws, you can't sleep in, at least on
DCL at St. Thomas since everyone has to clear immigration between 6:30 and 8 am before ANYONE can get off the ship.
We found St. Martin more interesting, did the 6 metre regatta and shopped....didn't have time for an island tour. St Thomas we did the Skyway and City tour and shopped, but broke that up by going back to the ship for lunch.
I'd at least try and step off the ship in all ports. But for some folks, the SHIP is the destination, and the ports are secondary. Only ship I ever felt I got to do everything on was on the MS Mermoz. But that was a small ship (583 passengers), and it was a 14 day cruise, and it had far fewer things to offer than the bigger ships. Never got to do everything on the Magic, Amsterdam, Norway, Nordic Prince or Soveriegn of the Seas.