To be fair, even a cursory examination of how much time and effort they get to put into these cases, they cannot.

I remember reading that a judge has, on average, spent 16 minutes or less on convictions for less than 1 year sentence.

The state makes it impossible for people to do that, even if they were so inclined in the first place. And, of course, they have to consider that they go against part of their own organization to make this happen (meaning some of your colleagues will want a conviction and you preventing them from getting that will have costs).