Isn't this what gets said everytime Twitter bans someone?
Cloudflare is allowed to offer services to people you don't like.
Nazis shouldn't get a website, even if the law permits it, and everyone has a moral obligation to fight fascism.
If you would restrict one then you restrict both. The freedom is absolute or it does not exist for anyone except the current favored group.
It's like laws on the treatment of prisoners of war - we don't have those rules because we love our enemy, it's because we want our brothers to not be tortured.
[1] because their business scales very well, so they'd prefer to be considered reliable, so that competition doesn't have that available as a differentiator; any attempt at applying content-dependent rules either uses lots of heuristic automation or is reactive in response to Twitter storms, neither of which is predictable and reliable
Not having the legal obligations of a utility, while acting like one (i.e., getting to pull the "neutrality" card in the face of public pressure to drop nazis) is not okay.