There were three reasons for this shock:

The scope of the fraud was massive
The penalty was, to a bank with a market valuation of $250 billion, the highest of any bank in America, trivial
Of the 5300 employees fired, not one was an upper echelon corporate executive.
Turned out that trench level people were being relentlessly pushed to produce new accounts, new credit cards, anything new that produced new fees, and so they did. Just without the knowledge of the putative account holders, even though they were being charged (or penalized, as the case may be) for these accounts.