I agree that part of the motivation for people supporting zoning is to preserve or increase their property values. But I think that people that spend a huge chunk of change on a house should care about preserving the neighborhood they bought into. As an extreme case, without zoning, what if each home lot on your street were turned into a high rise residential or commercial building? I don’t think any homeowner expects nothing to change, but they bought a house hoping that it continues to have a similar quality of life going forward. It’s not all about money. Peace and quiet is important to people, for example. Lack of traffic is important to people. Having one neighbor on each side rather than 100 is important to people.