Well, since only .5 - 1.5% of the population calls itself "gay," that's not a WHOLE LOT of decisions that the banks have to make.
Besides, NOT ALL homosexuals walk around with a badge proclaiming their homosexuality; nor do they all "look" homosexual.
Also, many folks bank on-line. I do.
I also find that I don't need to go to the bank that often. I can just go once a month and get all the cash I need.
I have business accounts with them and its going to be a pain, but they are moving.