Thank you for pointing this out. I keep seeing comments to the effect of "Wells doesn't make any significant profit from opening bogus accounts (unused accounts are typically unprofitable to the company), so the executives couldn't have wanted this." These comments reflect a misunderstanding of modern executive compensation and the incentive structures set up for executives in large companies like this.
What happened here is called control fraud [1], and it started at the top. Stumpf repeatedly bragged to investors about Wells' supposed cross-selling abilities, and these representations were priced into Wells' stock (being good at selling would suggest future growth). Because a higher stock price maximizes his own personal compensation (and his cash compensation, i.e. bonus, as well), the incentives down the line were set to maximize this metric. Tolstedt was in charge of the retail unit and her own compensation was substantially based on this same metric. This continued down to the low-level branch employee level, where the perverse incentive structure and ability to hire and fire (and threat of such) was guaranteed to produce massive fraud. The company and its shareholders do not benefit from this (they are victims, essentially); the responsible executives do, since this increases their personal compensation.
[1] https://en.wikipedia.org/wiki/Control_fraud. You should read more about what William K. Black (former federal S&L regulator during the S&L crisis, at the Office of Thrift Supervision and its predecessors; Keating Five whistleblower; and current economics & law professor at UMKC) has to say on this topic in general.