It's not that they're "anti-porn" it's that they're anti-risk. Porn sites have been getting in increasingly hot water for years for a variety of legal reasons, and all it takes is one major lawsuit against them trickling up to the payment process for enabling harm to set legal precedent and then they're getting sued for anything and everything on the basis they are enabling almost all kinds of web content.

It's an understandable fear. It's just a sad fact that they are an effective global duopoly so if they chicken out there's no alternative for people to turn to. More competition would help with this, but the threat of the lawsuit floodgates opening would still be there and create a chilling effect on payment processing. That has to be handled by legislation, but that's going down a whole other thorny road with many possible bad outcomes. The legislation we get may introduce new problems even worse than the ones it attempted to solve.

But I think it's still worth trying. The present situation is very bad for the future of an open internet.