I'm on the "car is a waste of time/money" boat
When you're in Vegas, you're either gambling, partying, or eating. All 3 of which aren't necessarily the healthiest when you're there, so the walking and sweating helps burn off all of that

I also think that walking the strip is part of the fun of going to Vegas, otherwise you're just going to any other city's busy touristy street i.e. Robson, Kalakaua Avenue, etc.