Because they're not all that way, and some of them still do genuinely try to "Protect and Serve"? And then you have the others mentioned "fire fighters", "teachers", etc, again many of whom are just tryin' to do some good in the world. Hunt all those good ones down and hold them up as examples of how the rest should be trying to do their jobs. Just complaining about the bad ones and acting like they're the only ones certainly doesn't make the situation any better for them or us.