Unless they were born or raised with empathy, which is an obvious no, nothing bad happens to them if they're terrible. A ton of enjoyable things happen, even.
At that point, you're weighing the opportunity to do whatever you feel like at no consequence against doing what other people tell you to do for none of your own benefit (the only measurement that matters). Technically at a moderate cost to the one reigning themselves in. Under the looming threat of nothing if you do not comply.
I know the question was purely rhetorical and born out of the same frustration that I have. But I wish we'd drop this weird notion the more humanitarian of us seem to default to, like people who do this shit just haven't had the golden rule properly explained to them yet. They know. And they've figured out it's currently a farce.