Also, it's not obvious at all that there's a messaging problem. I get that a bunch of white people don't like the message. But a bunch of white people will dislike anything black people do to push back against a system that harms them.
For decades white people have been telling black activists that they're doing it wrong. And their main cited evidence is that white people are uncomfortable. MLK got a lot of that, and he responded to it here:
https://www.africa.upenn.edu/Articles_Gen/Letter_Birmingham....
I certainly agree that the "Black Lives Matter" slogan makes me, a white person, uncomfortable. But as far as I'm concerned, that's just what it should be doing. If other people are being maltreated by a system that I have the power to change, that shouldn't feel warm and fuzzy.