Many of the shenanigans pulled by health insurers aren't legal, but they know a significant number of people will just pay or file bankruptcy instead of appealing or lawyering up.
Lawmakers need campaign money and shakedowns are profitable.
Think of all the times you've seen a news headline that reads "Company X settles with [regulatory body], does not admit guilt". Corporate malfeasance rarely reaches the courtroom, so their wrongdoing is not entered into public record in a way that can be cross-examined.