From what I could find on Wiki, being unfamiliar with the group, it sounds pretty much not only like my thesis is upheld, since as you say the Colombian drug trade is still healthy, but they also weren't truly vigilantes.

The group is alleged to have commited numerous human rights violations in Colombia, including torture, rape, and killing of civilians.

Unless, of course, rape and torture fall into traditional vigilantism. I understand that it's a group of people affected negatively with Pablo Escobar, but that doesn't give them the right to turn around and harm others in the name of justice, because that never ends.