From what I read of the Grand Cayman land-based shore diving 'scene,' particularly regarding a certain onus to rent tanks from onsite providers when doing so, I'm under the impression that, compared to Bonaire, Grand Cayman has much fewer mainstream shore diving sites, and the bulk of those have some sort of business that owns the property by which one would access them from shore. Thus while the op. doesn't technically own the dive site, from the perspective of shore divers, for practical purposes they control it. If a business owner is anti-solo diving out of liability fears or control issues, for example, that would give them considerable leverage.
This situation became sufficiently entrenched some people mistakenly believed solo diving illegal in the Caymans, though that is not the case. I suspect paternalistic regulatory practices grow as a society's government grows. Curacao is similar to Bonaire in some respects, larger and more populous, and seems less accommodating to solo diving (again, to the point some thought it illegal there), but it's not and some providers tolerate it.
In Bonaire, there are many shore accessible dive sites, many (I suspect most) publicly accessible without walking across private property in front of some business (it's not unknown; if you stay at Black Durgon Inn, Small Wall is a shore dive; if you don't, you'll likely need a boat). And the heavy emphasis on shore diving over a large area means a dive culture where unsupervised divers (some alone) with gear and tanks in rental trucks drive off dive op. property and border on un-(scuba)-policeable. I believe Dive Friends requires solo cert. (though off grounds I imagine that's unenforceable), and they made note I have one.
Bringing it back around to talk of regulations pertaining to dive boats, any time you have a commercial business such as a dive op. with paying customers, held accountable to government and insurance companies, you're going to have more regulation that we see on Bonaire shore divers. I imagine Bonaire's dive boat operations fall under such, also.
Richard.