Do you really think that "Black Lives Matter" is a confusing message? I think it is only confusing if you assume that saying that black lives matter implies that Latino lives, white lives, etcetera do not matter. Indeed, how does adding "too" clarify things? Perhaps that would only mean that black and white lives matter, and Latino lives do not matter. "All lives matter" is a tone deaf response. Of course we generally agree that "all lives matter" in some vague way. But insisting on "too" or "all lives matter" dismisses the reality that not all lives matter in practice. It reads "Black Lives Matter" as "Only Black Lives Matter," for whatever reason.
There is the controversy (albeit a small one) that the media don't report in
a major way about the even greater number of white guys killed by cops.
As they regularly say on NPR (my radio news source.....government
created, btw),
the problem is with "police killing African Americans".
They generally don't acknowledge the larger problem of militarized & violent cops
killing every ethnic group with impunity. It is reasonable to object to this focus, & to
broaden it. SJWs don't like it if anyone changes the focus.....tough noogies.
There's also some irony pointing towards the larger issue....some of the cops killing
\black folk are also black, eg, Eric Garner.