Because cyclists are narcissistic people who think the vast minority of people who live in cycling distance of their work and everything else and never get enough from the store or anywhere else that is problematic to carry back home (seriously, do these people ever actually get anything of substance?) think they need entire city blocks completely dedicated to them while giving a big middle finger to people who just want to get to where they're going directly because they CAN ferry any decent amount of goods back and forth.

Not to mention their massive ableism that ignores people who cannot easily walk or ride for any decent distance and denies them direct access to places. Cities already do this to a point where there's no actual free parking anywhere for people, even parking dedicated for them which, in the suburbs, every single parking lot has spots right next to the building for them so it's as easy as possible to access. Most cities rely on garbage paid parking decks and lots far away from most things people need to get to, and even if they have spots for those people, they're still not as accessible as the vast majority of places in suburbs.

Cyclists are basically like vegans and religious people: ignorant, hateful, and annoying. It's not "turning" into a culture war: it is a culture war, with rich, fortunate elitists on one side and the rest of us on the other.