Or, for that matter, why do any ATMs have Braille keypads? The display screen is not in Braille so a blind person would still be unable to figure out if the button they selected is for Withdrawel, Deposit, Stamps, etc.
They make them all on an assembly line and it’s easier (and less actionable) to put braille pads on all of them than it is to try and make some braille-less ones and put them in the drive-throughs.
They put them on ATM’s because it’s better than nothing. They can memorize the screens necessary for a quick deposit or withdrawal; I don’t think they’re trying to get account balances or transfer money between accounts too often.
The ATMs I’ve seen lately have instructions in braille on them on how to use the machine. I’d imagine (since the instructions are not also given in text and I don’t read braille) that the instructions tell the user about how to enter their PIN, which buttons to push for cash from checking and savings, and how to enter an amount. I’m sure it also includes a description of the sounds the machine makes (“When it starts beeping like all-git-out, remove your card”).
Plus, it’s conceivable that the blind user was driven to the ATM by someone else.
Taxicabs come to mind. I imagine if I was unable to drive to an atm myself, I might use a taxi, or ask a buddy to drive me. I’ve also been known to walk up to a drive thru ATM.