So funny how people think this is a moral crusade. You should read articles around the tech stack for payment processing at any adult site. People try to do chargebacks all of the time on these kind of services. "Hunny what is this transaction on our account for BigBussomsCom?" .. "Oh must be some kind of fraud" "then let's call the bank and straighten it out". It's variations of this, over and over that lead to the high chargeback rates. I seem to recall that chargebacks are an order of magnitude higher for adult-oriented transactions. Unless you have a system of countering this with a team devoted to it, you will have a lot of successful chargebacks. I doubt Valve has the specialized team needed to deal with the amount of chargebacks, this the CC companies trying to avoid the headache.