When Wells Fargo, or any other bank, lets their very experienced, well trained employees go they then will likely end up working for the competition.
They may then work for another bank, trained by Wells Fargo,with their great skills and knowledge now competing with Wells Fargo. It really is not in the best interests of a company to eliminate their long term, very experienced, well trained employees just because of a short term setback in business and profits. Instead, when business picks up again, they will have to hire and train new employees that will not acquire the skills of the laid off employees for many years to come. How is that profitable to the company?
If the outcome is dire and an end is near for the company so then fine. However IF the company plans to succeed better in the future keeping it's original employees will be the way to go forward.