Consider that it's common for anyone who suggests the impoverished of any race are more susceptible to police violence to be quickly and roundly piled on for trying to erase race or for supposedly engaging in “pity poor whites” rhetoric. It doesn’t even matter if “and impoverished black people even more so” is included. The fact that one isn’t solely focused on the racial minority in this context is grounds enough for social scorn and ridicule.
There is a very real problem with “oppression olympics” centered on racial identity, in this country.
> The impoverished of any race are more susceptible to police violence, and impoverished Black people even more so
is true. But the statement
> Black people of all economic classes are more susceptible to police violence
is also true. There is no logical contradiction between the two. Therefore, when someone responds to the second statement with the first, their response carries the connotation that the first statement is somehow "more true". It implicitly minimizes the struggle of Black people.
Not everyone who makes the first statement in response to the second intends minimize the struggle of Black people, but I think in the majority of cases that is exactly what they intend to do.
It's not even about making the statement in response, as you suggest.
There is no contradiction between the two, but only one of them is considered socially acceptable in certain circles, these days, in any context. That's problematic.
Because that catchphrase started in reaction to Black Lives Matter, and is used largely to signal opposition to the goal of constraining police actions. If people were holding All Lives Matter protests in opposition to police violence of all kinds, I doubt they'd get much flak; instead, they're protesting the idea that black lives matter.
Just because you say it means something to those people, doesn’t mean it means that to them. You don’t get to choose the hidden meaning behind other peoples words, and you’re clearly giving them the least charitable interpretation