Well, I think VD is even stupid when you have a girlfriend, but I don't really mind it. It's just much more fun and surprising to give (and be given) gifts or little... "Aufmerksamkeiten" on a regular day when you don't expect it, because that shows you think and care about that person all the time, and not only on special days.
However, when you happen to don't have a gf on that particular day, all the fuss about it only rubs it in your face that you are lonely.