That "defense" never really uses the full saying, does it? "A few bad apples spoil the barrel" is the full phrase. Without removing the few bad apples, what happens to the remaining apples in the barrel?
That's why we need to bring these "few bad apples" to the forefront. If they're left alone, or treated as part of the group, they'll either spoil the rest of the department, or the entire department will take the heat for just a few of their coworkers abusing their power.
Holding all officers accountable for the actions of few seems in poor form to me, though I have no data to back this up. To me though, it feels like we'll end up polarizing the LEOs that just want to do good work, much like how "Not all men" began.