Teachers are workers, too. They are some of the most overworked and underpaid workers in developed nations. So, teachers are good (as a class) and deserve our support.
While some teachers are assholes, most have too much shit going on to adequately delve into each topic they teach and engage with students. They have a set syllabus they have to follow that is dictated by the politicians (and capitalists). They can’t really afford to rock the boat.
Look at Knowing Better, who used to be a history teacher who peddled the same myths and bs as everyone else, because that is what is taught and that is what you’re forced to teach. It is only after he left the profession and got the time to actually delve deeply into American history that he learnt the truths that otherwise would remain hidden.
I really don’t think you can compare teachers and cops. They are more like nurses IMO.