For once, CEQA would actually protect the environment: Nowadays, downzoning requires an impact study. There's no way any credible study could conclude that promoting sprawl is good for the planet.
a) It would lower their home values (note that the railroad tunnel predates the houses by a few decades, and the railroad has talked about doing this project for 2 decades)
b) Extra train traffic means more pollution. Seems reasonable, until you realize that the tunnel is almost literally in the shadow (it's on the south side, not north, so not quite literally) of an interstate. Guess who's responsible for most of the air pollution.
c) The project calls for railroad to temporarily run in a exposed trench while building the tunnel. Residents are worried about what would happen if an oil tanker car caught fire. Unfortunately, a glance at the map indicates that this is not on the routes between oil supply centers and oil demand centers, and, as Baltimore found out (see https://en.wikipedia.org/wiki/Howard_Street_Tunnel_fire ), fires in tunnels are much worse than fires in the open air.
Yes, but this time instead of an individual development being up for CEQA obstruction (which favors NIMBYs), proposed rezoning would be subject to environmental review. This means pro-growth people could use the NIMBYs' own favorite tool against them, preventing down zoning. Poetic justice.
In CA, various state laws require that cities zone some parcels for new housing. Often, that housing never happens because cities can disapprove even zoning-compliant projects on those parcels. The by-right law is intended to fix that problem.
Unfortunately, the by-right law does not seem likely to pass the legislature. If you support it, you should call and email your state reps.
[1] https://leginfo.legislature.ca.gov/faces/codes_displayText.x....
[2] http://www.abag.ca.gov/planning/housing/datasets.html#report...