I think you can still believe in free speech as defined by the 1st amendment and still conclude that these companies acted ethically. Trump and his troglodytes have other ways to reachbtheir audience. They have not bee prevented by the force of law from saying what they want to say. The 1st amendment doesn't apply to private companies and nor does it guarantee a platform. There were platforms back when it was formulated (newspapers). So, i don't think it is a case of "platforms did not exist so the 1st amendment could not account for them"