This question has been asked for years and has spurred many debates. A few months ago this question came up in conversation between Glossy Eyed and a friend. They said that they never buy used games. Their friend came back with a short statement, why. "They don't go bad and, if taken care of properly, last forever."
Glossy Eyed didn't have a good answer why and it made them rethink how they purchase games.
As long as the game works, I don't care.