I haven't Rv'd south of the border, but I have traveled a lot to many of the less prosperous countries in Central and South America. Never had a scary situation, enjoyed friendly locals most everywhere, despite my limited Spanish.
But I think the countries' inability to deal with corruption in the police and security forces has destroyed their tourist industry. Tourists, especially from North America, can bring in huge amounts of income, but people need to believe that the police and security folks will help them if need be, not fleece them and collude with the criminals.
The ordinary folks, in this case good hard working Mexican people, suffer twice: from the crooks, and from loss of their livelihood. Sad.