I think it has nothing to do with deaths caused by DUI. I think it has everything to do with "being virtuous." It's the same point of view that made the woman who had the big red cups not worthy of being a teacher. Or that a couple or four decades ago made it impossible for a pregnant woman, in some states just a married woman, to be a teacher. PA is chock full of ridiculously repressive, regressive laws, and I think this is just one of them.
MACTECH ubi dolor ibi digitus