Cartels do not only sell drugs, they are systems of diversified private security corporations and paramilitary groups which have emerged out of the previous iterations of violence and loss of governmental order which was a symptom of national narcotrafficking disputes in the previous decade. Basically a large portion of the Mexican Government effectively is infiltrated by cartels which also function with public support, hence the mudering of journalists and politicians...cant have people speak out and show that cartels are bad now can we?

If you had a time machine and could boycott drugs in the 1980s then it would have had an impact...now not as much.