Because Madoff scammed rich people. You can get away with a lot if you scam the poor. Not so much when you target the wealthy.
The more you look like a high-status leader, the longer it will take, and the more likely it arrives as a fine or a suspended sentence followed by an eventual redemption story published in the New Yorker or equivalent.
But targeting other high-status people ejects you from the white glove treatment.
In fact, in that exact case the chap who did it was treated far too leniently by the justice system and they've un-"Progressived" the law in some ways to make it so he would never be able to do that again. Which is progress. Or at least the undoing of Progress.