What happens if all other providers refuse you as well on same basis? What if Comcast refuse you to provide any internet service because they don't like your views on net neutrality?
In my personal opinion, the size of "all others" matters.
If you have a monopolistic ISP that refuses to provide service to you because they don't like your content, and they're your only option, then that's a problem.
If you have multiple tens of CDN providers and they all don't want to carry your content, then perhaps you should really take a look at your content and have a hard think about why it isn't wanted.
And regardless, a CDN isn't necessary to host a website. A CDN certainly makes it easier to achieve lower-latency global reach, and is useful in helping you weather certain types of attacks on your infrastructure, but they're by no means required. And there are other ways to achieve those goals.
Exactly, with similarity being a second important thing. For example, maybe you’re lucky enough to have three ISPs to choose from, but they’re all big American companies with nearly identical corporate cultures, and odds are good that if one of them kicks you off, the others will too.
Hosting a site, on the other hand, has a multitude of very different providers to choose from. Even if you manage to get banned from every hosting provider in the US, ship a server to a colo in Kyrgyzstan or whatever, and keep right on going.
