> You could just ask, "why do payment processors pressure content vendors not to offer this kind of content". You're starting from the premise that there's some weird puritan thing happening, but there's really nothing puritan about American business culture. There are other explanations!
Someone, somewhere is making a choice to pressure content vendors to not offer this kind of content, and not to pressure them to not offer other kinds of content. It may be upstream of the payment processors but there is absolutely a weird puritan American thing going on somewhere, and it's much more interesting to get to the bottom of that since that's the point where change could happen. If everyone involved was amoral, these profitable games would continue being sold.