Well, at least Twitter did have a rule which allowed people the US gov't had on sanctions list to have accounts. As well we had other heads of state protest bans on other heads of state.
Obviously, your intuition differs, but my view (as a New Zealander) is that Trump absolutely broke the terms of use of the platforms he was on and deserved being banned. Free speech means that you can't be imprisoned for your political views, not that everyone owes you a platform.
It does mean more than not being imprisoned. For example, if the government came to Facebook and told them to remove all posts by a certain politician, violations of the platform’s rules notwithstanding, I believe that would also be a violation of America’s first amendment.
They said his comment "We have to have peace. So go home. We love you. You're very special." and "from great patriots who have been badly, unfairly treated for so long. Go home with love in peace. Remember this day forever!"
As "praising or supporting people committing violence".
He literally said "we have to have peace" and "go home" and that, to you, is "deserving being banned"?