> The way I look at it is that the incumbents are there due to mostly accidents (of birth time/place) or of luck. Why should newcomers be disadvantaged due to accidents and luck?

Most things are accidents of time/place/whatever. Including whatever resources those newcomers are bringing to a city. Is migration and density growth a strict good? A strict bad? Somewhere in between? Lots of ink have been written on that, I'm fairly personally neutral, but I'm very skeptical of the "this is a simple problem with a simple solution" crowd. I'd love to see a decentralization of high-end high-paying jobs. Right now if I wanted to live back near my family, I'd have to work on problems that are less interesting to me for quite a bit less money.

There's nobody exactly being unselfish in this debate... People who want more density or to save their own money argue one way. People who want to live a (different) way argue another... it's basically all wants considering we have so many other cities in the country with plenty of space.