The "Good Cop, Bad Cop" trick is a popular technique because it works even when you know they are doing it. The contrast between the 2 operators makes the less extreme one look mild in comparison, even though they would appear anything but mild in another context. But it doesn't work only with police. It can take the form of "good pope, bad pope" or "good Supreme Court Justice, bad Supreme Court Justice", or even "good media outlet, bad media outlet". Now that you are aware of this trick, you will see it everywhere.