I live in the highest density cycling city in North America (Montreal) and this is not anecdotal. A huge portion of my office cycle-commutes to work, and the vast majority do not shower. This was doubly-true before I worked at my current company, where there weren't showers, and still most people used bikes to commute.

At what point do anecdotes from people who actually live this experience day to day become more useful to listen to than theories from people who don't?

I used to commute by bike myself (and would still if logistics allowed), so you should probably not presume.

The fact is, short of linking to professional analysis and reporting we are all here relating anecdotes - and that's ok.