So it all has to do with the extremist movement to censor online content. The argument is that 'anybody' can access Adult content, even though most of the situations there are verification, filters based on age, parental controls, etc. Since these groups weren't gaining traction on the platforms (i.e. Steam) these groups started harassing the payment processors themselves. Because the processors don't want to be held legally liable, they threaten to pull the ability to process payments through those channels (aka no more Mastercard / Visa unless you give in to our demands). So this is all or at least largely in part due to the monopoly that these payment processors have on the market. Obviously if your business is strictly online and the majority of your money comes from transactions from Mastercard and Visa, you're going to do what they say lest you risk losing the majority of your business. As a side note there has been some progress made in Europe to break up that duopoly. I don't know a lot so do your own look up but there are other payment processing options. If you can, do your part and support those companies!