Legalizing drugs by itself does not imply that the price of drugs will fall and that the violence will end. Lest not forget that, in Latin American, revolutions have been fought because of the impact of the exploitation of the people and land for the cultivation of commodity products such as bananas (see Banana Wars in Wikipedia) and for which gangs like La Mara are a consequence. Drugs for personal use are legal in Mexico, so the violence itself is not related to the criminalization of drugs, it's related to the profit of drugs. And legalizing drugs only strengthens the cartels grip on that profit (see OPEC).

The one key aspect that I often find that is missing from the intellectual reasoning of the drug cartel violence in Mexico is that most Americans don't understand that narco culture that exists in Northern Mexico. For over 30 or 40 years, there has developed a narco culture in Mexico where songs and movies have been influenced by the trade (see Chalino_Sánchez). Basically, Chalino_Sánchez was like the Mexican Jay-Z except he didn't sell out and was gunned down by an unknown assailant.