Are you suggesting that most tourists going to Cozumel are divers?Really, divers are 100% not part of the problem despite most being tourists.
How many cruises ships docked at the harbour ?
One thing I am pretty sure that vast majority of tourists who arrive at Bali(6.3m visitors)and Phuket(9.8m) have nothing to do with diving. Cozumel only draws 5m.
I do not come from Philippines.I dearly love visiting and diving your Philippines, but I saw more industrial scale destruction there than I could have imagined. Still, much to see, but many localized zones are just forever gone.
Over last 10yrs only FOUR places have any sizable modern development for tourism. Mactan Island in Cebu, Malapascua, Panglao in Bohol and Puerto Galera in Mindoro. And only Malapascua and PG is diver destination(95%+). Alona Beach on Panglao used to be like that unfortunately scuba diving is now playing second fiddle to tourists with different idea. Pity.
Great diving is still available for the time being.
Tubattaha(Lob) is the best option. Only destruction so far is mainly caused by nature and illegal fishing practice or careless navigational skill of US Naval Captain.
https://www.rappler.com/nation/us-navy-ship-damaged-coral-in-tubbataha