It's a good question, and I think we need to figure out where that line is.
Because I agree, AWS should be able to say they don't want this customer. At the same time, when we live in a world where everything is privatized (and monopolized) you very quickly run out of options. Host it yourself? What if all server companies refuse to sell to you, or the internet service providers refuse to provide you with connectivity? Do you need to lay your own fibre and fab your chips? Where do you get those supplies? It's tough.