I think there is a difference between the concept that you pay for the service plan you have with your ISP - which is a voluntary economic relationship based on use- and the concept that the general infrastructure with its concomitant investments past and future in technology is a public utility akin to the interstate highway system.
The other concept that comes into play is honest labeling. Comcast offers "internet access". If they arbitarily pick and choose which content providers can be accessed at the full speed their individual customers paid for -- or even which ones can be accessed at all -- they are not providing genuine internet access. It's no different, really, from a grocer selling something that purports to be a pound of beef but which actually weighs only thirteen ounces, or which contains thirteen ounces of beef and three ounces of vegetable filler, dead bugs, and sawdust.