I agree. I've addressed this in this thread a few times. My argument is not that it always works. It's not that it works X% of the time or that it is preferable to Y action. It's basically:
1. This is the natural result of years of injustice not being solved by those in power. We must fix those injustices if this is to stop.
2. That violent riots, which often include looting, frequently do work, and so its utility has to be understood when analyzing the horror of these events.
3. News media/individuals which try to argue that violent protests solely serve to obfuscate the message of those oppressed peoples are simply spouting shallow garbage that intentionally ignores the reality of history.
Those journalists and individuals that spout shallow garbage are part of the backlash that often makes violent riots an ineffective way of fixing the very injustices that spark these riots.
I conjecture that violence is not rendered completely ineffective by backlash only when a very large fraction of the population already sympathizes with the movement, but if the movement has such a large following, it could probably accomplish its goals without resorting to violence...
Given this, I don't think I could defend or advocate the use of violent protests to accomplish social goals, unless presented with evidence that I'm wrong. That said, I also understand that anger and violence are at times inevitable, and I would personally prefer that the public would focus instead on fixing injustices instead of scorning the angry protesters. However, I also understand that just as violence is inevitable, so is backlash to that violence...