"We can't kill them all!"
So we should kill zero? This is the same logic that says of we can't catch all border jumpers, we should not try to catch any. If we can't stop all bank robberies then we should not try to catch any. This is erroneous thinking. OK, we can't kill them all, or apprehend 100% of the border jumpers and bank robbers, so let's kill/catch as many as we can.
This isn't rocket science. I saw the Tucker Carlson segment in question, and I think he's just playing devil's advocate, because just about everybody else on Fox thought the action was the right one.