The law undoubtedly offered considerable peace of mind to holders of normal checking accounts. But it also had an unintended consequence: In the eyes of banks, Dodd-Frank transformed low-balance debit card holders from potentially profitable customers into almost-guaranteed liabilities. Israel estimates that a customer now has to maintain an average checking account balance of about $25,000 before a bank can profit from it. Making matters worse is that the big banks are experiencing a sort of hangover from the boom era before 2008. In those years, the banks were giving out loans so feverishly that they were gladly adding checking account customers simply for whatever additional capital they could provide. Now all those checking accounts they added in a binge can pose a burden. Without the ability to levy harsh overdraft fees or charge as much for “swipe fees”, there simply isn’t much incentive for banks to keep debit card users aboard at all anymore.

Bank of America’s early October proposal to supplement its lost “swipe fee” revenue using a five dollar per month charge to holders of debit cards should probably be understood in that context. It was designed to be a win-win proposition for the bank: either it earned $60 per year from each debit card customer with a checking count under $20,000 (more than making up for the estimated $28 per year the banks used to earn from each debit card from the “swipe fees” that Dodd-Frank disallowed)—or it would drive unprofitable customers away from the bank entirely (or at least toward Bank of America credit cards, which have become more profitable than debit cards), to the benefit of the bank’s bottom line. As finance expert and Roosevelt Institute fellow Mike Konczal told me, “This whole thing was to nudge people back onto credit cards. People who use the credit cards can be incredibly profitable.” Reuters journalist Felix Salmon goes further, writing that this move was meant to push out the customers “at the margins.”

Ultimately, the Bank of America and its competitors chose not to go ahead with the five dollar charge, deciding that the hit to their PR wasn’t worth the potential gains to their bottom line. As Diane Casey-Landry, a former CEO of the American Bankers Association told me, the public outcry against BoA was enough of a “reputational kick in the chin” that its top competitors—Wells Fargo, Citibank, and Chase—abandoned their proposed debit fees as well.

But in that way, the Bank Transfer Day enthusiasts are only doing Bank of America, and other big banks like it, a favor. By interpreting the new charges as another example of greedy perfidy, rather than as a way to boost profits by driving unprofitable customers away, the organizers are doing the big banks’ bidding.

To be sure, banks know they benefit from having small depositors as a “sticky” base of core customers: Since these customers' checking accounts are federally insured, they are less likely to make a run for it at a time of financial crisis, unlike the bigger, uninsured clients upon whom the banks currently depend for profits. But by fleeing the big banks, and making them more profitable in the process, the Bank Transfer Day participants may only be encouraging those banks into basing their business models on short-term calculations.