Its one side taking things too literally and failing to read inbetween the words and another side wanting change so bad they feel they need to make it be as serious as it can sound.
Then the correct response to "not all" would be "Yeah, absolutely not all. But enough that it's unsafe to assume for a randomly selected member of the group that they don't, which makes it just as bad a problem as if all of them
were," which would cut that argument off at the knees. Instead you get what happened in this thread and happens in discussions like it across the internet.
Truth of the matter is that "not all" is probably correct in pretty much all of the cases where it's an issue, but in the same way that you only need a certain small percentage of people to be anti-vaxxers to cause epidemics of deadly diseases, you only need a certain small percentage of, say, cops to be genuinely fucked-up levels of bad to cause the equivalent in law enforcement. And it seems pretty obvious to me (and probably to a lot of people who'd argue 'not all' when faced with the extreme view) that in the US not only are they
way over that percentage, but the whole structure of policing seems geared to increase the numbers that are, and decrease the numbers required to make it a problem.
Not all doesn't matter. Even not most wouldn't help. Hell, even not the vast majority wouldn't make a difference, particularly with the way the structures in place work. It's not a point worth arguing (for or against) because it's so fucking irrelevant. The only thing that's going to help is major reform of those structures, and then systematically removing the ones who
are bad, one by one and permanently, however many there are.
