I've cruised often, and will be doing so again. Many cruise pax are well-aware that the ship's excursions are way over-priced, and they actively seek local options for excursions. It's usually first-time or novice cruisers who buy the ships' overpriced excursions. I almost never take the ship's excursions. I research beforehand and often link up with fellow pax to hire a local driver/operator (with a website usually) who offers something better at a better price. This is what Terry is doing in Samana.
People who get off the ship for excursions for the day almost always spend some money (some more than others). They do want to see something of the country, even a little slice of life in that six or so hours. The cost is usually about $75 per person, unless there is equipment involved (catamaran, zip line, ATCs, like that). Then it's about $150 per person. People expect to get a small minivan or minibus with about 10 in the group. This, by the way, really beats the ships' excursions, where they load 60 or so people into a bus, and at every stop everyone has to wait and wait and wait for the slowest person to get back on the bus. The six-hour excursion usually includes a pretty nice lunch featuring local foods, and a beer or rum cocktail two or three times along the road. People want a guide who speaks intelligible English, and who tells them about the lives of people in the country as they ride along. They want to stop where there are nice pictures to take. They want a lesson or two, so they feel they are learning - this is a banana plantation. Let's get out and I'll show you the banana plant, and you can see how little bananas start, etc, and so on. They'd like to hear about the last earthquake, hurricane, etc., and learn about how the people cope with these problems. They like to stop at a beach for 45 minutes or so. Then they're pretty happy to get taken back to the dock. Cruise pax taking independent excursions live in fear they will miss the ship - better have a backup plan in case the van breaks down. They don't mind a short souvenir shopping opportunity, but enough is enough. And no touching, pestering, blah blah blah. Just makes them want to jump back in the van and get back to the ship.
They want to know they will be safe throughout the excursion, and their purse won't be snatched. They want to see how other people live in a different place. But above all, THEY WANT TO GET BACK WELL BEFORE THE SHIP IS SCHEDULED TO SAIL. There can be no fail on that point.
Terry (from what I read on the Cruise Critic boards) has taken it a notch higher. He's actually managed, through word of mouth, to get people to bring stuff for impoverished Dominicans (good for him). So people love his tours even more because they bring socks and coloring books and whatnot, and they get to give them to kids who seem to need them. I don't think this is cynical, but if those cruise pax thought they could have their tour and help needy local village people at the same time, that would be a winner. It is for Terry.
Those who get off the ship and stay near the dock just want to have a look around. Leave them alone and don't pester them - they're not gonna buy anything anyway. Or, they want an honest taxi price to the nearest nice beach, with a guaranteed pickup time that is honored. On the beach, they expect to take a lounge chair associated with a beach bar, and they want to order beer, margaritas and snacks that won't give them diahhrea. And have a decent toilet to use.
I do recommend anyone interested in serving the cruise ship market take a good long time to read the Cruise Critic website. You can learn everything you need to know there.