It's not about hiding. If they're arrested while at head of those companies, the companies stock tanks. Stepping down and arresting at later date saves an economic hit on top of the effect that the news itself will have.
I can understand having doubt about someone you admire and look up to. But appearances can be deceiving and deception is the name of the game. Wealth is relative and having a name guarantees you'll never be completely broke, but that sympathy probably opened doors for him that wouldn't have been opened had he remained wealthy the entire time. What better way to guarantee a positive outcome then to rig both outcomes in your favor. NN and his Declaration of Independence guaranteed control by those institutions the clowns had already infiltrated.
We might find out one day he was only enabling the clowns to use his operations and not an active participant, but looking the other way is just as bad. Once the story is revealed, we'll know for sure.