Cabo is the only place in Mexico I would visit. They are far off the routes of the drug trade, and have no industry to speak of other than tourism, so the city fathers and police forces go to considerable lengths to make troublemakers unwelcome.
I haven't been there since the hurricane. But I'd guess Cozumel may be a bit isolated from the drug war, simply because it's an island for divers that the gangs don't bother with. Pure speculation.
We’ve been on a cruise to Mexico and visited Puerto Vallarta. I’ve always wanted to try Cabo but at this point my husband refuses to spend one red cent in Mexico.