There is also an irrefutable (if uncomfortable) logic that, if you know who the baddies are and leave them be, you have a degree of knowledge and control over what goes on.
That is what informants, psychologists, intelligence etc all feed into.
While it might rouse the hoards to say "We'll wipe out the cartels!" or whatever, even if you did succeed, you'd just leave both a power and information vacuum behind.
A new band of baddies, about whom you now know nothing.