Making it seem like it's predominately something done by middle-class men, or even rich people, helps to undermine public support for it because of the image people have of a stereotypical male cyclist, ie a well-off person riding a $1400 bike with a bunch of lycra clothes and tech gear pretending they're training for the Tour de France while they go through their midlife crisis. It's much less relatable an image for many people, who might say "Well, why do they need to ride on all the roads? They can just go on the paths in the park, or if they have so much money, they can go to a purpose-built facility."

If you frame it as though it's just going to benefit a bunch of people perceived to be living it up, you can drum up opposition from poor people, who don't want their taxes going to fund some BS project that only benefits people who are already doing alright. Your aunt that's busting her back trying to make ends meet and is trying to get back and forth to work and the shops on a bike one step up from a Wal-mart special can be much more relatable for many people who are struggling to keep up, can't really afford their car payment and might even use a bike if there were dedicated bike lanes. So people looking to discourage building out bike infrastructure will naturally prefer that everyone thinks the only ones who would benefit from these developments would be some middle-manager who owns his home, rides a bike that costs more than your rent and that has gone on more vacations in the last year than you have in the last two decades.