There are actually strong, non-"puritanical" reasons for this. An oft-cited anecdote is the spouse or parent that finds mysterious porn charges on the credit card. Sex-related services carry an extremely high rate of charge backs. The transaction risks are much, much higher than other categories of goods and services.
So while Visa could simply charge more, there are numerous other headwinds that make this tricky. Political will, payments risks, brand risk, and deep rooted family/social stigmas that fuel the rest. They kind of all have to be dealt with at once for this to start making economic and business sense.
For proponents, it's going to take generational change to shake all of these network effects out. The first step of which is consumers (Gen Z?) publicly admitting that they see no harm in sex-related commerce and to begin showing this in their purchasing behaviors.
John Oliver recently covered this as it relates to sex work. Stigmas and dispositions are changing, but it's slow. A lot of signalling has to happen to a lot of people.
None of this explains why the banking industry blacklists porn stars from having checking accounts, nor why they allow other high-risk industries wholesale access...the gym industry, for example, is incredibly fraudulent and yet the banking industry has no problem letting them use ECH, a system so permissive it's a fraudster's wet dream....or why the banking industry has done nothing to self-regulate payday lenders.
> An oft-cited anecdote is the spouse or parent that finds mysterious porn charges on the credit card. Sex-related services carry an extremely high rate of charge backs. The transaction risks are much, much higher than other categories of goods and services.
I'm not sure how they're working things on the payment processing front but Steam has sexual content on it's regular storefront now without requiring external patches. Heck some are even Steam Deck verified.
“A lot of signalling has to happen to a lot of people.” More signaling makes all signals weaker until everything is noise. Probably not the desired outcome.
...steam is covered in ads, even opening them in a separate window when you launch the client. They're only for stuff sold on steam, and publishers (supposedly) can't buy ad space, but they're ads nonetheless.