Maybe the publishers would be reporting profits if people felt like they actually owned the game after they had paid for it like they do with console games. I know it's not as simple as that but being told I can't even GIVE a game to a friend after I've finished with it because I'm breaking the law is not the sort of attitude that gets me to fork over my hard earned money to someone!
Copyright law needs to update to reflect the fact that technology has changed and what was acceptable twenty or thirty years ago isn't now.