Payment processors banning companies from using them for anything other than illegal use or fraud issues seems like pretty egregious overreach to me.

They shouldn't be able to leverage their nigh monopoly on modern payment processing to choose winners and losers in the marketplace.

They are using pornography as a wedge issue to establish that they get to dictate what companies are allowed to exist in the modern distributed market.

It would be entirely reasonable to legally require them to act blindly towards retailers, with restrictions needing to be based on universally applied financial criteria.

Card payments have become inseparable from modern life.

Regulate them as a financial utility. The electric company or water company can't refuse to hook up a business just because the owner doesn't like that business.