The granede incident in P. Vallarta was just that. A stupid men bringing a grenade (not granedes) to a "sleezy"bar. Wanted to show this to his friends, and it went off. No tourists will ever come to that bar anyway.
Apart from that the drugsproblems are mainly in the borderareas, not in the touristic areas around the Mexican Riviera. Of course all tourists worldwide (not just in Mexico) have to pay attention whre to go and what to do.
I am sometimes surprised by reactions of people not realising that many of their own hometowns are sometimes more dangerous...
Read the recently published article in "the Economist
Mexico: Mexico: safer than Canada | The Economist