A riot is the voice of the unheard. You're looking for rationality among the oppressed in the face of the irrationality of the oppressor. Why do the oppressed have the obligation to be somehow more rational? Why is it any less logical to destroy an area in which you live (and to be honest, a CVS in Baltimore and a convenience store in Ferguson aren't really the high water mark of community pillars) but why is it less logical to destroy those places than to allow cops to kill black people and get away with it?

You're asking the wrong questions I think.

More importantly, and this is a bit more daring, but the uprisings should be condoned because violent uprising is the only route to actual changes. The feds came into Ferguson and Baltimore for oversight of police actions after the uprisings. The Civil Rights Act didn't get signed because of people sitting in neat little rows making clever arguments and begging for power to be given to them. It may be an uncomfortable truth, but power isn't given willingly to the oppressed.