I came back from Maui at the beginning of this year, and one of the locals at one beach I absolutely loved to snorkel had all her snorkeling information, and a huge gallon sized jug of "reef-safe" sunscreen. Hell I assumed sun-screen would if anything float..
As to the tourism vs ornamental. I
saw what tourism was over there, tourism was a bunch of boats and people going around feeding fish so you'd get a swarm of them and be able to say "look I have 100's of fish swimming right near me... (instead of "only" 20 or so). Some of the larger companies claim they don't sell fish food, but there are so many other places that do that it's really a non-issue, Snorkel Bob, Boss Frog (two of the bigger ones I'm guessing) only take a couple boat trips to Molekini. When I hopped over to Kauai it was even worse, granted the beaches I went to were very undesirable (and the surf was pretty rough so I didn't attempt too many places) but what I did see was again people walking on the rocks because they don't have
flippers, luckily for them they didn't get their feet all sliced up, but that is probably due to the fact that there weren't many corals nor skeletons. Some guy decided he wanted to touch a sea turtle, and he did, I almost got a picture of him doing it too, but I did remind him when he surfaced that you can't do that, which he didn't seem to care about until I mentioned $10,000 fine.
So yeah Tourism vs Ornamental hobby... no comparison about what brings in more money, but as for destructive practices? I don't have an true proof either way, but from what I saw, I would say Tourism destroys more than the ornamental industry.