ISPs are natural monopolies [1]. In the US we're seeing increasing market share concentration by some pretty big juggernauts in the space (Comcast, Verizon). So what you're seeing is a lack of ISP choices for consumers and in many instances only 1 choice and that in my opinion is far more problematic than what Google and FB are doing. I'm not defending censorship by any party here really, but I definitely think censorship at the ISP level is a much bigger problem.
1. https://en.wikipedia.org/wiki/Natural_monopoly