Also, the residents were probably interested in increased property values, just like all home owners are.
I see people assuming this a lot but I really think it's in bad faith.
There are plenty of reasons to oppose unbridled development that have nothing to do with property values. Some people like where they live and moved there because of what it was. The idea of an area becoming something totally different might understandably be problematic to them.
The traffic concerns especially resonate with me, as I currently live in a place that has few sidewalks and no effective public transit - previously "walkable" neighborhoods are no more as their density increased and they are flooded with cars.
Maybe as a society we can reasonably decide that such real concerns do not outweigh the benefits that may come if we increase density, but not everybody chooses where to live or what to advocate for based purely on financial concerns, and to dismiss those other concerns does a disservice to their points of view.
The neighborhood next to it fought the proposed zoning changes. Too many houses near by, increasing traffic, too close to the creek, etc. Probably more likely they were worried about property valuations changing. Ultimately they got their way, and they never got past the planning stages for that neighborhood.
However, it didn't stop development on the property from continuing. Since it was already industrial, they went ahead and started building an ugly. massive, tilt wall warehouse on the property. It didn't need many reviews and got approvals very quickly.
So now instead of some nice houses, a park, and a few small retail spots to help increase the massively supply constrained housing stock in the area we're going to have a probably busy warehouse with large trucks coming and going constantly deep in the heart of what is otherwise a largely residential area. Nice going, NIMBYs. I bet that warehouse is going to help your property values quite a bit.