I don't mean to belittle what you have reported but do want to try to put
things in proper perspective.
I live in the U.S.A., state of Kentucky. A couple counties east of me a 2 year old baby, her 10 year old sister and 31 year old mother were all murdered and their residence set afire. This was yesterday, not a year or two go.
A couple counties south of me a young mother was abducted from a store parking lot, brutalized and left for dead. This too happened a couple days ago. Also, ( and again within the last 2 days, ) a Mexican man was found murdered here in my home city. This isn't by any means a complete list of the murder, rape, robbery and mayhem that goes on around my neck of the woods, much less what happens in a days time in the country as a whole.
Maybe the Mexicans are responsible for all this ??
The point is, there's crime everywhere. The U.S is one of, if not the most, violent countries in the world.
I have been to Mexico many times and never had a problem. That's not to say I won't sometime or the other, but by using common sense I would probably be as safe, if not safer there than here at home.
I can't wait to get back to Cozumel and Costa Maya in September.