I dove there a couple years ago. Was with a group that decided to go and didn't really know much about it at the time. Certainly not as good as getting to see one "in the wild", as they were mostly on the surface and there was a petting zoo atmosphere about it (not that there was touching, but can't think of a better term.) Some clarifications-
-the rules say no touching and to stay a certain distance away. This seemed to be followed by divers, not sure about snorkelers. I can see where there could be at least incidental contact with snorkelers simply because they're both on the surface and the rules say nothing about what the sharks can do...
-you don't get to feed them yourself
-they're not restrained in any way (other than the free lunch, which they don't all necessarily seem to show up for all the time. There were only a few there when we dove, which I think is a subset of the individuals that might show up.)
There were plenty of rules, and a required briefing on the rules, but at the same time the whole thing seemed pretty disorganized and seemed like it could be run better. I would say the main concern with this is how it might affect the behavior of the animals. And I often saw the fishermen feeding the sharks push or kick them away from their boats, not sure exactly why, and I wasn't too happy to see that. It clearly does something for the local economy, and if this hadn't developed might be one of those things where the sharks wouldn't be as well off. Supposedly whale shark protection rules led to the feeding starting (ironic as that is) and the business presumably provides some incentive for the locals to protect them, possibly more than rules do.