Contrary wise, consider a Jewish payment processor who wants to knock off a Nazi store. You can’t have it both ways.
Bigger problem is that for most real world problems who is Nazi and who is Jewish depends on who you ask. Sucks to be Jewish in a Nazi world where even payment processors hate you.
It's clearly not the case at all. Valve wants to sell third party games. Third party game developers want to sell their games. Customers want to buy third party games through Valve. Do you understand this bit?
A payment processor company is far excluded from the process. Users want to pay Valve money. Valve wants to receive the user's money. All fine, right? Except a payment company somehow feels entitled to tell Valve which products in their product line they can sell. WTF?
Going back to your far-fetched example, it would be like a supermarket selling all sorts of products their customers want to buy, but the Nazi bank somehow feels entitled to tell the supermarket they should not sell any product related with Jews. Does that make sense to you?