[disjhshava]

This type of construction is only so profitable because it's usually illegal, and therefore a critically undersupplied segment of the market. Developers are therefore eager to do it every chance they get. If it were legal to build this way everywhere, they would only do it in the places it made sense. Developers wouldn't be building 4-story condos in Contra Costa county for people to commute 50 miles into SF and Mountain View if they were alowed to build enough to meet demand in SF and Mountain View.

Where people want to build, the power-hungry folks in charge put restrictions in place and demand a troll toll to let a few projects through. And the folks in charge where nobody wants to build see the opportunity and seize it. It's just human nature, and it's the reason local government shouldn't be put in charge of density regulation.