Why throw 20,000+ people out of work?
Although it's unfortunate that jobs would be lost, this fact can't be used as a get-out-of-jail-free card, either. When the sole bread-winner in a family goes to jail, there's a good chance that the family will lose its house and car, etc., but the person still has to serve the time. It might be mitigated, but the courts don't simply pat them on the back and let them go free with a relatively infinitessimal fine.
An alternative: for the full term of the sentence, the corporation becomes the property of the state, with all profits going to the state, and all board members' corporate holdings being frozen during the term of the sentence. Further, board members can leave the board during the term of the sentence but must forfeit their stock in the company to the state if they do so.
We must also get rid of "no admission of wrong-doing" as a feature of plea agreements, and fines must be sufficient to punish the corporation. Such fines should not be permitted to be written off as losses for tax purposes either.
Corporations are fictional entities constructed by legal process. There is no real reason why the law can't be corrected to hold corporations accountable.