I actually follow a similar rule for my own code but only because of printing code to an A4 page - 80 columns is about the right width for my desired font size.
But that's personal preference and probably not what you were after (since you want ammo to go the other way).
What don't you question the reasoning behind the limit - seriously, if no-one can come up with a good reason why it's so, you have a good case for having it removed from your coding standards.
