Taking away many billions from billionaires is worse for them than detention.
And charging companies with fines is ridiculous IMO. There are always humans who made decisions ultimately. And charging companies (not them) is just a "get out of jail and enjoy Hawaii" card for them.
After they cheated, they probably had the promotions, money, golden parachutes, and left the company after bleeding it out and hurting it anyway. So why would you charge the company a second time ? Why not them ?