well.. not the best example. California and New York combined have 3-4 times the population of all the Nordic Countries.
Or how about we look at their relative land areas[2] (not counting Greenland) - California & New York only have 41% as much area as the Nordic Countries.
0: http://www.wolframalpha.com/input/?i=((california+population...
1: http://www.wolframalpha.com/input/?i=(california+%2B+new+yor...
2: http://www.wolframalpha.com/input/?i=((california+state+area...)
The fact that wireless sucks in the big cities of the US is indicative of crappy service, not technical challenges.