Adult content is considered a high risk merchant category - meaning it is susceptible to high chargeback and fraud rates. This is because after someone pays for and consumes adult content, a certain level of "clarity" overcomes them resulting in the execution of chargebacks against the merchant.
It has nothing to do with any sort of puritanical premise.
They should instead charge a higher transaction fee on those items to cover that risk
Do you think this happened because Valve was getting lots of chargebacks? I don't.
Just plain wrong and a puritanical group already claimed responsibility for this
That sounds like a reasonable argument. We should force them to make it publicly with data. Maybe even force them to release aggregate statistics every quarter going forward.
That seems disingenuous. (1) in this case, this is a not a tiny fly-by-night wannabe game company. (2) which is good for paying back (or never seeing) the money of chargebacks.
For a new company, the risk of chargebacks might rest on a credit card company (for a little while anyway). But not for a long established one.
I don't think that can explain why they're only targeting certain sub-categories of porn, and it's also contradictory to the public statements by Valve:
> We were recently notified that certain games on Steam may violate the rules and standards set forth by our payment processors and their related card networks and banks
Individual games violating "rules and standards" doesn't really fit with prohibiting a category because of high rates of fraud.