i live in LA and my take is that people in single family dwelling residential blocks often resist construction of higher density buildings because quality of life goes down (i.e. more cars on the streets, more smog, traffic, noise, unfamiliar people, potential crime, less access to government resources like schools and law enforcement, per capita, because those resources are not built out as fast as population growth in LA).
so, the proposal becomes: if these new zoning changes allow apartments on your block, you'll reap a 200% gain if you sell your house today, but you'll immediately lose backyard privacy, quiet streets, sunshine in parts of your yard, easy access to the freeway, and so your enjoyment of life will decrease and you'll have less free time outside of work, etc
my take is simply that a lot of people think the price increase isn't high enough. if they want to keep their existing job in LA, where are they going to move to with that 200%?
now, if the number were 2000% instead of 200% maybe zoning changes would be uncontroversial...