Land is expensive because everyone wants to live within the same 5-mile radius around the "good jobs". There's lots of land in the U.S; there are very few corporate headquarters of growing companies.

At the same time, it's hard to fault buyers for this. Commuting sucks (what price do you put on 2 hours out of your day?), and the difference between a "good job" and an "okay job" can be an order of magnitude in income these days.