I'm not going to weigh in heavy on the debate(s). I'm a 3 year bike commuter in Denver, and I use no MUPs. It is the EXCEPTION when a driver doesn't give me a reasonably wide berth, even on roads with small shoulders. I was hit by a car once, it had nothing to do with my commute (riding from apex trailhead to chimney on my MTB). Guy stopped, made sure I was OK, drove me to my car, and cleared everything with his insurance.

Denver is a fit city. Most drivers are into some sort of outdoor activity themselves, some even cyclists.