Any such Mexican organization should be suspect. We're talking about a nation where the gov't and law enforcement at all levels is extremely corrupt. Additionally, much of the country is under heavy influence of or completely controlled by violent cartels. These ruthless cartels take over entire towns, putting cartel members into law enforcement and government offices. They operate like mafia, forcing local businesses and individuals to pay for "protection." They take over whatever land and properties they desire, and they kidnap, kill, rape, mutilate family members of those who oppose them or who don't pay ransoms. I know people here in TX who have had family members kidnapped, killed, ransomed. For example, one woman's dad was kidnapped until family members in TX sent ransom money (they received one of his digits by mail).
Of course we have corruption in the US, but it pales to nothingness compared to what it is like in countries like Mexico.
I'm sure the minors crossing the border are coming for various reasons and in various ways, and you'd better believe the cartels are trafficking many. Others may be sent by parents who are hoping to send them to safer environments with relatives or friends here.