Mostly agreed, but there are a thousand legitimate reasons to resign and that act shouldn't remove them from their profession. Same with getting fired. Who hasn't had an asshole boss or been fired unjustly (or at least known someone who was)?
We need to hold the police force who re-employs the asshole cops accountable. Sure, hire 'em! But if they step out of line just once, that force is getting sued into the ground.