I don't think I agree that "police are bad people," at least in total; but I think what they're saying is that the police as an institution exist to protect the wealth of the wealthy, not to protect the lives of the poor (and further are expressing the idea that anyone who voluntarily enters that field is more interested in protecting property than people).

I think there are many reasons people become cops. Some want a feeling of authority. Some want to feel like heroes. Some want to hurt people. Some want to simp for billionaires. Some—maybe the minority—want to help. Probably most cops got into the game for a combination of those reasons. The truth resists simplicity; particularly personal truth.

But one thing that isn't oversimplified is that the modern institution of policing was created to protect the profits of slaveholders—the capitalists of the 1800s—and our laws, written by capitalists, have done very little to shift that mission.