While admittedly the US has a different density and settlement pattern, there are a lot of places in the US that aren't physically that different than the Netherlands, and their paths weren't always as fantastic as we see today.
This video, produced by the relatively new Dutch Cycling Embassy, gives an excellent history of the social movement in the 1970's that transformed the bicycling landscape. This video implies that the lynchpin of the movement was concern over child safety, and I'm curious if that was indeed the main focus, or if there were other historic preservation/ density concerns.
There's definitely a virtuous cycle a brewing. More facilies= more cyclists=demand for better facilities=attracting more cyclists, and at some point you end up with the political will to create a comprehensive cycle path network!