Dealing with big businesses whose services you need to conduct the basics of everyday economic life can be frustrating when those businesses make seemingly arbitrary decisions that cripple your ability to function in a modern economy. In general, the incentives of businesses are to, well, do business with customers.
It's not surprising, then, that a recent New York Times story giving infuriating details of innocent Americans being cut off by their banks reveals that the real cause of the banks' seemingly arbitrary behavior is government rules designed to make sure it knows everything it can about citizens' banking business, to discourage big cash transactions, and to ensure businesses the government disapproves of have as difficult a time as possible without being explicitly banned.
As the Times puts it, when citizens suddenly find their banks exiling them, it's because "a vast security apparatus has kicked into gear, starting with regulators in Washington and trickling down to bank security managers and branch staff eyeballing customers."