What if they host their own shit on a VPS but the hosting provider bans them. What if their domain name gets revoked by the registrar?
You can either make things a public service, try to codify into law what content a business must and must not engage in faster than content changes, or have some content businesses are not going to host.
And it doesn't have to be universal. E.g. you could decide DNS and internet access need to be a public service but since those two are always available you don't need to try to regulate the content on VPS since self hosting is an option.
Well fuck alt right too! They can get their own website after all. Why should Medium or any other company have to host their shit? People act like they have some kind of right to have their crap hosted by someone else. Companies are not public services after all.