Um, all BLM has to do is wear merch and hold up a sign and the police start lobbing CS grenades.
The point of protest isn't to riot, but to get the state to over-respond, brutally. Its why the entire world knows about and sympathizes with the BLM cause.
At least that's the game, according to COIN. Hearts and minds. Though in the Civil Rights movement, we added lawsuits.
And Trump and the red states are quick with their riot squads. Left wing movements just have to represent and make booga-booga faces to trigger anti-riot shooting civilians with rubber bullets. (They're plastic and steel, actually.)
And then two years later, the victims are awarded millions from the districts or the US treasury, depending on the department of the officer who decided it was time to bust heads.
Law enforcement in the US has already lost its legitimacy in the public eye, worldwide. We know they're just thugs of the state, and their response to protest, especially minority protest, especially black protest, figures largely into that paradigm shift.
So, just because protesters in the US still carry signs instead of molotovs, doesn't mean the protests are weak. It means the state's responsers are incredibly easily trolled into initiating violence while camers are watching.