I think it simpler than that. White collar crime isn't punished because half the government would be in prison if it were. Your average city government is at least as corrupt as your average corporate organization, and probably much more so. And it gets worse the higher up you go. The government operates essentially like the mafia, only it's legal when they do it.

It’s not really for reforming criminals into a normal person, that would require a rehabilitative system purposefully optimizing for lower recidivism rates.

What we have is a vengeful, punishment oriented prison system that is designed to bludgeon people for not fitting in, and also incidentally using them for slave labor.

I don't understand the point of prison. Vengeance only makes sense if you have committed a crime so great that you could never undo it and the only way to balance the situation is to take an equal amount of damage as the victim.

That's an even stronger argument in favor of prison time for white collar crime because you cannot rehabilitate the perpetrator, you can only punish him.

Meanwhile for someone who is prone to violent behavior it is the opposite. That person still has the potential to do less damage in the future.

That’s because reducing crime is really a secondary benefit of prison as practiced in America.

The primary reason for its current form is to appease the “fire and brimstone” folks who think that crime must be a result of inherent moral failings that can never be stamped out, so it’s simply what those folks deserve. It’s the flip side of the so-called Protestant work ethic. Go to literally any news article regarding a crime, and there are still plenty of eligible voters who want even more tough-on-crime, as if that has ever solved anything.

For reasons of a systemic nature, people seem to not call for this so passionately for white collar crime or the type of criminals who tend to perform it. There are very rare exceptions like Bernie Madoff but that is the exception and not the rule.