> Is the difference between the First Amendment and the moral principle of free speech really that nuanced?

It depends if you're trying to win elections or internet arguments, or to ensure a healthy marketplace of diverse ideas exists, because that is the best way we know of to find the best solutions to problems. Twitter, Facebook, YouTube are where modern people "congregate" and get their "information". Cutting someone off of these platforms dramatically lowers the chances that anyone will hear them, that's the entire point of the action. Claims that dismiss this as no problem "because someone else's platform" are not just saying nothing illegal has happened, they are also essentially saying a free marketplace of ideas is not valuable. This is a very new development in western countries, and it's pretty easy to see how far gone most people are already, even on more intelligent forums like this. Partisan politics trump almost everything on certain topics, even one as important as this.