Because if zero tolerance policies taught us anything it's that across the board punishment, even for people who have little to no control over the action, is a great idea?
That's pretty much the status quo for employment. When Enron went under, we didn't say "Well, the janitors didn't have anything to do with it, so they keep getting paid." If you work for a company and some at the top does something stupid, you're going to get punished for it, ever though you had nothing to do with it.
Honestly, it almost forms a neat free market solution to corruption. A savy insurance firm should start offering Employer Corruption plans that would pay out if you lost your job due to a conviction of the company. Shadier firms would have higher insurance rates and thus would have a harder time finding employees.
If my house catches fire and I don't have insurance, I don't get a new house, even though if I didn't start the fire. If my company goes under and I don't have insurance, I don't get paid, even if I'm not the person who wrecked the company.
Ah, but that's dealing with individuals and not the corporation.
But I also don't understand the lack of criminal convictions. The article mentions damning internal documents that show individuals within the bank knowingly breaking the rules. Why aren't these people being charged? They shouldn't be protected simply because they were working for a large corporation.