The cartels are not terrorists. I greatly despise the cartels and they are the prime reason (alongside the failure of all Mexican administrations since Calderón to deal with them) why I dislike going to Mexico, but they are not terrorists and believing they are so is a sign of ignorance on the subject. Terrorists are groups of individuals who engage in extreme acts, typically violent, to intimidate, terrorize, and cause fear amongst a population usually due to opposing point of views. ISIL and Al-Qaeda terrorized others because they weren't Muslim or largely opposed their radical Islamic ideology. Mexican cartels aren't terrorists, they are criminal syndicates that use violence as a way to distill fear against other cartels and the Mexican military. The cartels couldn't care less about religious point of views or even ideologies, they don't care about that at all, they care about making money and continuing their illegal rings of drug, sex/human, and arms trafficking. They are crime organizations that have infiltrated the economy of Mexico and hold it hostage, but they don't commit acts of violence randomly just because, they do it because of turf wars and confrontation against the government. You can imagine the Mexican cartels as being pretty much like the gangsters and mafias that ruled New York in the 1970s, just with US military grade technology and weapons.

Labeling the Mexican cartels as terrorists is the same as labeling the US military as terrorists.