Power and water are public utilities (as is internet, in some parts of the world but not all). Payment processing is not. If you want to argue that it should be, we’d likely agree.
Well as long as they are independent businesses, why shouldn’t they?
If your argument seems to be “they are too crucial to be independent businesses,” I don’t think we’d disagree too much, but the fact is that they are right now.
Kind of cuts both ways though, doesn’t it? The reverse of this argument is saying that the payment processors must work with Valve no matter what they host. Agree it disagree with them, but don’t the payment processors get a say in what they do or do not want to process?