Private equity is capitalism. That's the capitalism part of the economy.
Doing that to a company isn't an activity that should be rewarded since you're destroying, rather than creating, economic value. It is absolutely an exploit or flaw in our system and no more than one person should have been able to get away with it.
Restricting a previously purchased business from taking out debt feels harder to regulate, but someone smart could probably figure out a few good rules to stop the majority of abuses.