The proof, as they say, is in the pudding. From my reading of bike forums, and general observation of guys pulling kiddie trailers on local bike trails, there seems to be no lack of fatherhood in the cycling population.
That being said, with all the talk of uncomfortable saddles around here, it is more than possible that a largish percentage of men have had problems, probably seat related. Or they have an important vein in just the wrong place. It's possible, and certainly something to be aware of, but really, I think the so-called friend was just being a jerk.
Give big space to the festive dog that make sport in the roadway. Avoid entanglement with your wheel spoke.
(Sign in Japan)
1978 Raleigh Gran Prix
2003 EZ Sport AX