Actually, in the hearing Senator Warren tried to connect the fraudulent accounts to the stock price, which would have been a direct benefit for the bank:
> You squeezed your employees to the breaking point so they would cheat customers and you could drive up the value of your stock and put hundreds of millions of dollars in your own pocket. And when it all blew up, you kept your job, you kept your multimillion-dollar bonuses and you went on television to blame thousands of $12-an-hour employees.
http://www.nytimes.com/2016/09/23/business/wells-fargo-tests...
Wells Fargo pushed its employees so hard to open accounts because there was a benefit to doing so.
They created two million new accounts, letting them go to the market and tout demand for their banking services.
http://www.bloomberg.com/news/features/2016-08-18/how-lendin...