I didn't say that all dentist-types are vehicular cyclists, just that all vehicular cyclists seem to fall into those two groups. One-way taxonomy. If you advocate for accessible bike infrastructure, good!

I'm actually white and male, myself. Fit, though I'd stop short of claiming athletic. But for me, taking up cycling was an eye-opening first hand example of disperate privilege. Both in how cycling is treated compared to driving, and how level of access to cycling itself changes depending on who you are. While I was already primed to understand social justice, cycling is a small way for white bros to really emphatically experience it along one vector, even if temporarily. Some of us gatekeep it as a result, but like you or I some of us use that experience as motivation for advocacy.