Dude, if nobody buy drugs, what power does the cartel has? NONE, old money, mainly televisa owners, politician owners and several other big groups saw how gringos party so well with drugs, so started imitating them, order to start growing in several, states, then come the gringos who needes cheaper drugs than colombian to keep their minories under control and pay with weapons, then cartels started going on, get some militars from centroamerica, and voila, higher ups didn't give a damn because they get their cut and nobody can touch them, el peje even bow dow to one cartel leader mom.
Old Money starts the problems, i know that very well, in Yucatan, back in the days when Cervera Pacheco was the main old money power, he forced cartels to bow down to him, and make them a deal, the could use yucatan as a temporary aerial base in theri trips from colombia to florida, but they couldn't sell any drugs in Yucatan, and menwhile Cancun was full of drugs, Yucatan was clean, of course, when he died, the deal was off.
Cartels are not the main factor of corruption, the governmen is, the goverment motto is keep population stupid, trow them some leftovers and give them futbol to be happy, ever sind the Revolution ended, that has been the reality in mexico, el peje just keep that going, cartels are just the flashier case of corruption, neither the main or the origin.

well i mean if they didnt there would definitely be conflict. imo the mexican government doesnt have many options and none of em are good.