What would be the real truth: is Mexico harboring them, or are these people using Mexico? My cost-benefit analysis says that making a whole bunch of Mexicans angry that we blew up their neighborhood in search of actual bad guys will cause the survivors to side with the bad guys. I'd expect the government to do something about it, but to me this is the wrong something and far excessive.
Turn it on its head. If the cops, while searching for a really serious criminal, blew up your backyard because they suspected he might be hiding there, would you be totally cool with it, because, in the end, they might get the bad guys?