Public polling is very YIMBY too, they are the majority.

It's just the public input process is a filter that selects for extremely high activation, interest, and agency. So if a democratic vote ruled these decisions, YIMBYism would rule the day, but if you go to the meetings it's NIMBYs who are prevalent.

There are definitely centralized NIMBY groups, like Livable California:

https://www.bloomberg.com/news/articles/2019-07-26/how-to-br...

And there are tons of smaller groups that organize locally, far more than YIMBY groups. In my city there are 2-3 people that typically organize a group, give it a new name, make a web page, and act like they have the backing of everybody in the city when they talk even though most people disagree with them. They've been doing it for decades, and have found many tactics to amplify their voice to be much larger than the sum of the individual group members. YIMBYs are far behind on doing this, though they are getting better at it.

When I first joined NextDoor about a decade ago I dared speak up in favor of a plan to allow apartments to be built on a commercial thoroughfare, and the onslaught of a single person in their replies and direct messages was completely overwhelming (If people here think I'm loquacious, well, I have been far bested in that....). That was my first entrance into city politics, and I quickly learned that this person was in charge of a large "group" that mostly consisted of that single person. They had also been doing it for years, with creative group names, the best of which was probably "Don't Morph the Wharf" which even launched lawsuits to prevent changes to the wharf, delaying necessary maintenance and repairs which a few years ago resulted in the front falling off of the wharf. Individuals can have very undemocratic impacts on local politics.

Ish. Polling is very YIMBY. So long as it is exactly what I want in my back yard. With a lot more leeway granted to what should be allowed in someone else's back yard.