Where would the authority come from to force Amazon to support a message board they believe is for the purpose of inciting and organizing violent insurrection?
Why shouldn’t Amazon be able to make judgements about who it’s safe to do business with? Why should Parler’s decisions about who to do business with override Amazon’s?
Suppose Amazon did something Parler didn’t like, and as a result Parler decided to move to a different provider... should Parler be forced to stay with Amazon after all?