I don't think the article's comparison with Denver is particularly fair. Looking at Denver's municipal website shows that they have a main fleet of 70 large plowers, and a smaller fleet of 26 4x4 plows which are used to create paths for residential streets as a smaller plow isn't really suitable for clearing large avenues and highways. Secondly, and perhaps more importantly, is the type of snow that falls in Denver. As a high altitude, inland location, Denver's snow is mostly dry and fluffy, while an East Coast city like New York is often on the edge of some rain/snow border and wet and/or slushy snow is far more common (and far, far, far heavier).