I think there are a few major problems here:

There legitimately are powerful people who are systemically oppressing non-whites/non-straights.

There is a significant amount of people that lack empathy and have never experienced personally this type of systemic oppression, and thus don’t believe it’s real. This is particularly evident on the right where empathy is in short supply. See also: my abortion is the only moral abortion, the government shouldn’t be supporting these freeloaders (but make sure my HUD/food stamps/social security show up on time!), Obamacare needs to be abolished (but don’t drop me from my insurance I need my meds!), etc.

Back to point number one, even the blue team has been unfortunately ignorant about the level of systemic oppression and often serves as a validating factor. It’s one of the small things that I think have been positive about the social media era, these stories are getting to far more people than they used to. When I was in school in the 2000’s, if you asked basically anyone in my predominantly white school (including me, tbh) they probably would have said racism is basically a solved problem and is only a tiny little fraction of the actual experience for POC/LGBTQ++, etc. People with empathy pick up on this faster, but if you say ACAB in a room full of blue team, you’re probably still going to get a lot of pushback…

Speaking of ACAB, a big part of the problem is that people just do not fucking get nuance. Most of even the staunchest ACAB supporters don’t believe that everyone who is a cop or will become a cop is a bastard/bad person, the point is that the institution of policing in this country is systemically racist, systemically corrupt, and systemically insulated from consequences in a way that is unjust and bad for society. Or, shorter, we have heard of the Stanford Prison Experiment, and know that when you give people this type of power you can expect bad things. Thus, there isn’t a way to be a moral cop because the system removes the ability to stay moral, which is also why a lot of those that we would call “good” cops are forced out of the field. Anyway, pretty fucking hard to fit that on a bumper sticker, so we end up with things like ACAB/BLM/Pride, etc.