I've heard and seen "Black lives matters!" so often that I can't tell anymore what people think they're saying.
Black live matters! , a slogan I suspect originated with a sarcastic note to mean "at least" matters is being repeated ad-nauseaum like a tired meme.
Assuming that people of a certain skin color might simply not matter is racist to such an extreme that it can only be understood as sarcasm.
When things get repeated out of context they're likely to be remembered by many for their literal meaning.
Anti-racism protesters should try getting more creative or the overused BLM slogan risk conditioning some into eternal victimhood.
When dealing with complex situation of inequality, popularizing a scandalous new term isn't helping to reach balance in the long run.
It makes me think of when I hear the word "feminism" I can't help but hear "pro-woman" while it means "equality between sexes sprinkled with an arbitrary amount of retribution". Eternal victimhood or catchy remains of sarcasm?