Characterizing Cozumel dive practices, including the swimthroughs, with the words "body count" is completely off base, unless you feel that way about basically every dive destination in the world outside of your own classes.
Cozumel is a very safe location for divers with a strong track record to prove it. Every day there are hundreds, many hundreds I suspect, of safe dives, every day of the year, year in and year out. Of course someone's going to occasionally die. It also happens crossing the street, choking on food, and getting struck by lightning. And I dare you to find any statistical evidence that Cozumel is any less safe as a dive destination than any other ocean dive site.
As I said about a hundred pages ago, this accident alone does not indicate any need to change anything in the Cozumel dive op practices IMO. If something like this was a regular occurrence, that would be different. The absolute bottom line in diver safety is that each diver is responsible for his/her own safety and dive behavior. That includes getting trained well, diving with self discipline, know your OWN limitations and psychological/physical state, and ultimately taking responsibility for yourself. Of course the buddy system carries with it some implied responsibility for another diver, and in dangerous locations one had better be VERY picky about who one dives with. But aside from that, when all is said and done, certified divers are responsible for themselves.