I never thought about that, and yes I can see the issues blind people would have.
My father-in-law is blind, but he just strolls to the local stores and gives them his wallet, they take the proper money and give him the wallet back. Everyone knows him, knows he is blind, so they look out for him. Of course, that is tiny island life, where things actually still work like that, but in a large nation it's a whole different ballgame...so yes, unless it's an undue cost, why not slap some braille on bills?