A distinction without a difference. For all intents and purposes, it's racism.
No, it's a very, very important difference.
Replace 'poor' with some other grouping and meanings can change dramatically if you still want it to be race instead of the group as the cause of something.
It's especially problematic if "criminal" is the grouping. You have people who then believe that the police arresting a black man for committing a crime is racism.
It also prevents people seeing that yes, the police may treat poor white people and poor latino people badly too which dramatically changes the dynamic - the problem is not with the group or the community but with the policing. When it's made about "black communities" then they inevitably become the focus which I don't think helps change policies or attitudes as easily.
I'm not saying it's right or wrong, just describing the situation as I see it.
We all make judgments about people based on appearance and our prior experiences. It's "wrong" but part of our species survival instinct.
The police should ideally treat everyone 100% the same but it's naive to believe that someone dressed in a smart suit will be treated the same as a shirtless bum. Based on their experience the two will likely behave differently. Of course the shirtless bum maybe a millionaire and the smart suit maybe rented but usually there is some basis for the attitude.
The attitudes also work the other way - is it fair to judge all police offices just based on their wearing of a uniform?