You are getting nothing but angry pushback, so I am here to let you know that at least one lemmite agrees with you.
I don’t know if ACAB is a disinformation campaign by Russia and China, but I do know they have been stoking the division here in many ways on social media, so I feel you are not “fringe/crazy” for wondering if it is true.
I know a few police and fire responders, who are Latino and are stand up individuals. They are not racist.
We must strive to differentiate the fiends from the people who only want to do the right thing and resist the easy trap of generalization.