The article fails to mention that in both Korea and Japan, the government played a major role: In Japan, by forcing the incumbent to allow multiple IP operators to use the fiber at very low rates and in Korea, by construction subsidies. This isn't really technology competition as the article calls for - all the countries with cheap broadband use fiber-to-the-home or fiber-to-the-apartment-complex, with CATV playing a relatively small role. (There's very limited WiBro, the local version of WiMax, deployment in Korea, which plays almost no role.) And, as far as I know, all those countries have deployed such cheaper and more advanced infrastructure without violating network neutrality.
The argument about population density might explain the absence of DSL and fiber in Montana, but doesn't exactly explain the high cost of FiOS in New Jersey (or its limited availability). The population density of New Jersey is very similar to that of Korea, at around 400-500 people/sq km.