Rezoning empowers the existing landowner to do what they want with the land, within reason. Newcomers don't have any "moral right" over the land but neither do existing residents have an absolute right to dictate what happens on land that isn't theirs. Nobody's forcing people to bulldoze existing housing to increase density, but lifting arbitrary density restrictions give the current set of owners more power over their own property.
If nobody wants to force anyone then what's the complaint? If the municipalities are maintaining their desired zoning, it's for a reason and they perfectly well have that right.
Clearly the communities as a whole are trying to maintain an environment they like, and which they already have, not trying to create in anyone else's place to suit themselves, and the zoning is doing exactly the job it exists to do.
I see no reason that more people have to cram in to a place that is already full to capacity according to it's desired density level, until such time as the country runs out of space anywhere else.
Should a community be able to vote to exclude people who don't make a certain amount of money? How about people of a certain race or sexual orientation? These are freedoms that supersede the desires of the community, and since the single-family zoning laws are roughly paramount to gatekeeping by income, it makes sense to eliminate them.
I will note again that eliminating the restrictive zoning also doesn't equal a mandate over what landowners must to do with their land. You're welcome to keep your plot as-is. You just can't tell your neighbor what to do with their land.
No one is excluding based on class. They're simply full. You have no right to be somewhere where someone else already is. Prices are only high because a bezillion people want to try to get in the same place. Just go live somewhere else and there's no more problem. This argument that since there's not enough housing for all the outsiders that want to move in, they must build housing for you (or change their desired zoning) is completely entitled.
The municipality IS keeping it's plot the way they want it.
0.25 acre plot is not a country, it's a part of something else, and at that something else level, it is valid to make the same sorts of decisions for themselves as the homeowner does for their lot.
I would hate life in an HOA. What I do about that is I don't move into an HOA, not to move into one and demand that they let me raise chickens on "my own property".
I think I was 15 years old or less the last time I thought zones were some sort of travesty of injustice. Same a taxes.
I don't see why municipalities have any right to enact zoning, or really anything at all. Municipalities are just conveniences for the state, and municipalities should only have the power that the state gives them.