Tech companies aren't deciding what viewpoints are allowed. They are exercising their right of freedom of association.
Parler's moderation policies caused their own problems. They decided they wanted to be a platform friendly to violent extremists. Their noted lack of moderation of violent rhetoric, calls to violence, and planning of violence made them a pariah.
Amazon is free to associate with whoever they want. They don't owe service to Parler or anyone else.
So tech companies are editorial institutions? I thought they were platforms.
And it's not as if you can just go to the social media network down the street. Sites like Parler are trying to be those alternatives, and it's a tough business to even be #2 in.
Higher quality people might not like the seedy pawn shop in that strip mall with all the WW2 memorabilia, but that doesn't mean they shouldn't be able to try to do business.
Where do you get me suggesting cloud provider companies are editorial institutions? That's just asinine. By choosing not to business with Parler they're exercising their freedom of assembly. They can't be compelled to do business with Parler. This has nothing at all to do with editorial anything. AWS is just infrastructure you pay to use and have to agree to their terms of service.
No part of AWS or Twilio fall under common carrier regulations. They can choose with whom they do business. They would and do cancel service for clients doing illegal things or against their TOS.
Amazon doesn't owe Parler a viable business. Parler made themselves into a toxic environment that drove third parties to abandon them.