In all seriousness, I think you may be right.

I've noticed within Denver city limits, you see a lot more casual cyclists wearing what I would consider street clothes. The further out into the burbs you get, the more lycra you start seeing.

Its about land use. Denver is a lot more dense than many of the surrounding burbs. Bicycle trips would be shorter. Makes it easier to cycle in street clothes.

I know on my short 1.5 mile trip from the Park n' Ride to the office (which is out in the boonies), I'm the only one I ever see cycling in street clothes. The two or three cyclists I see every day are usually wearing cycling specific clothing. On my 3.5 mile trip from home to the bus station, I see a ton more casual cyclists in street clothes.

My commute is also strange though as I commute from downtown to the burbs... Denver is set up that way though. During rush hour, doesn't matter if you're headed into or out of downtown. You're stuck in traffic.