We've been to Jamaica twice, both on RCCL, once into Ocho Rios and once into "Mo" Bay. On the trip my DM was on with us, she did not get off the ship and kept our then (toddler) DS onboard with her. DH and I took ship sponsored excursions both times, and had a great time both times.
On one trip, we did a horseback ride with Chuka Blue that went through an old sugar plantation and along a beach. They then took the saddles off the horses and had us ride bareback (more or less) on the horses while the horses swam in the ocean. It was absolutely gorgeous, and a wonderful trip.
On the other trip, we went to a botanic garden and climbed Dunn's River Falls. Again, we were impressed with the beauty of the island, and had a wonderful time.
We were approached by vendors wanting to sell us things or braid my hair, and while they were the most aggressive of any port we've been to, we said, "no, thank you", and never had any issue.
We enjoyed our time there, and we would get off the ship if we happened to be there again, but we would go with a ship's sponsored excursion only and go straight back to the ship when we were done with it. We wandered around the port shopping area after one of our excursions, and we might do that again, but only in the the fenced area near the ship. We are comfortable going off on our own in most ports, but we would not do so in Jamaica.
I do not consider it a plus that
DCL is going there, but I don't consider it a particular minus, either. It isn't a port I would go on a cruise to go on, now that we've climbed Dunn's River Falls, but I'd find ways to enjoy it if we happened to go there again. It really is a stunningly beautiful island. Yes, there is a lot of poverty there, but that is true in far too many places, sadly.