That's a bullshit excuse.

I live in one of the largest cities in the USA. AT&T's 3G sucks here. If I go 15 miles west of here, it's suddenly way faster. This is entirely because AT&T doesn't invest in backhaul infrastructue. It's got nothing to do with the density the country, and everything to do with the lousy infrastructure investments of the wireless carriers.

Wireless in this country sucks cause we don't demand better. If it's socialist to want my government to go after these bloodsucking bastards and make them provide better service for the exorbitant fees they charge, I'm content to wear the red armband everywhere.