I am the same way, and I know it's more me than them. Perhaps one day I'll be more tolerant of drunks again. Last night I was at Penn Station in NYC and there were two drunks passed out on two different staircases. I took a deep breath, stuffed down my personal scorn, and said a prayer for them.
I was out one night with some friends, and one of them drank too much, as she is wont to do, and tripped over an uneven place on the floor and fell down. Her jeans were too tight and she was having a hard time getting up and she was right next to me. I looked down at her, called to her bf, and said, "Please come over here and help "Jane". Then I looked down at Jane and said, "Sorry, I don't pick drunks up off the floor anymore." They are still laughing about that one, including Jane.