I've tried to do this many time and have to say that most of the AI's make being a lone diver difficult and expensive. Most of them won't let off-location dive shops pick you up, and so you have to slog out to the highway, take a cab into town or pay ridiculous prices to use the in-house dive ops.
The most success I've had was at Dreams Tulum, where they didn't hassle the local dive guide that picked me up, and I spent a week diving some really cool cenotes. Dreams didn't have an in-house dive op, and so that may have been the reason they were so lax. They also had the best kids club that I've ever seen.
The worst was this last month when I stayed at the Gran Occidental XCaret and stupidly decided to try out their in-house shop, Barracuda rather than cab it into PDC. They sucked, and made me jump though hoops to get a refund. They actually sub-contract their cenote dives and had "forgotten" to book the dives I'd paid for.
I have a lot of friends who rented condos in Puerto Aventuras and had a great time booking through the local dive shops/guides. I think the next time, I'll be pushing my family to try this option.