Homeowners want to see their investment appreciate, plain and simple, and will do anything and make up any justification to impede development so as to reduce supply and increase home values. Pretty much any argument, any rule, that restricts housing ("ruining neighborhood character", "affecting the historic value of the neighborhood", and in almost all cases, "environmental impact") can be understood if seen through the prism of selfishness. Never mind that people's lives are more important than obtuse feelings of 'neighborhood character', and never mind that the reason the shitty silicon valley house you bought in the 70s is worth millions only because of the blood, sweat and tears of all the people who came here and started companies and built things.
As you can probably guess, I'm pretty disillusioned at probably not ever being able to ever afford a place to live in the place I call home. (And I'm a relatively well paid engineer, others have it much worse).