EDIT: To be a bit more productive about this, I referenced Guerra et al. [1] which shows that cycle commuting seems to be negatively correlated to income in the US and sharply negatively correlated with single vehicle ownership and positively correlated with being male. But this is just commuting and we know that there's more to transportation than just commuting and commuters tend to be more male as a whole anyway.

[1]: https://www.sciencedirect.com/science/article/pii/S136192092...

People don't tend to notice the guy riding his Wal-Mart mountain bike on the sidewalk on his way to work.

And they also don't tend to notice all the sensible, practical, riders who know to take the (relatively) car free residential side streets en route to wherever they need to be.