Look I'm not arguing with you here and I agree with all of that. I'm speaking 100% tactically and realistically here. If BLM (and I have no problem with BLM they seem like a perfectly valid protest organization) decides to keep pushing rather than taking a step back there is no scenario where they benefit. It's against their stated interests to keep up the full court press.
We aren't dealing with protests anymore. It's active rebellion on a scale we can't grasp yet. And BLM is caught on the front lines of it, literally face to face with the riot police and military. That isn't where protestors can accomplish anything. They just get hurt.
If we allow this rebellion to continue, rather than de-escalate where we can, we risk the inevitable outcome of all rebellions, successful or otherwise. Violent repression.
Even rebellions considered successful are always followed by repression. Take the US, for example. Despite what people learn in school, the US spent 1789 to 1865 repressing and squashing dissent and rebellions. If you add in reconstruction and the civil rights era you might even say that it never stopped. Russia. China. Cuba. The Arab Spring. France.
Every single rebellion is followed by violent repression. The only way to avoid it is not to play the game. I would say we were going down that path until recently and then we just lost it.