Why isn't fitness equipment designed more like arcade games?

I started thinking about this because I saw Wreck-It Ralph last night, and went to gym this morning and... maybe I had an epiphany??

Shouldn't treadmills and lat pulls and everything in between be designed like a video game? Imagine racing against someone on screen on the treadmill, or challenging the computer to a lat pull competition. And the game encourages and challenges you as you go.

Seems like it would make working out a LOT more fun.