One factor is the ongoing campaigns from number of moral crusading groups who lobby them to cut off payment processing for things they don't approve of. NCOSE has been working for decades on the project, and targeting credit card companies has been a successful tactic for them for a decade or so.
[1] https://www.eff.org/deeplinks/2020/12/visa-and-mastercard-ar...
[2] https://www.newsweek.com/why-visa-mastercard-being-blamed-on...
[3] https://scholarworks.iu.edu/dspace/bitstreams/761eb6c3-9377-...
One thing to notice is the group that claims responsibility for this is some kind of funky radfem puritan mixture from Australia. They campaigned against titles like GTA V, Detroit Become Human AND abortion pills.
Since they ran a campaign to ban GTA V from stores I can say for sure they are not stopping on fringe content like eroge porn shovelware.
They tried to do the same to OnlyFans, but lost that battle
To be clear, these campaigns seem to be grounded in fear, not any sense of morality.
Another factor is the board members and other investors of the institutions themselves.
I have been privy to two specific instances where pressure to either ban or reject providing support for specific content was handed down from beyond the executive level at a major financial network player that my client was doing business with.
https://www.washingtonpost.com/business/2022/08/01/visa-mind...
Visa being responsible for CSAM isn't a theoretical lawsuit they're afraid about. (2022)
The US obsession with sex (both positive and negative) is something else.
Here in Europe, sex is a normal part of human life. Not a center of everything, nor a sin to be avoided. Sex art is normal. Sex games are fine. There are no moral crusaders here, because sex is moral. We tell sex jokes at work and nobody faints. We are constantly perplexed why American culture is so different from other Western cultures in that regard.
People keep saying "Puritans" like it answers all questions, but Puritans were hundreds of years ago. We had our own share of people with peculiar attitudes back then. Today is 2025, not 1785.
As usual, the actual “cancel culture” comes from the conservatives.
It's easy to dismiss all such campaigns as religious prudes and moral crusaders, especially on a site with the demographics and political leanings of YC News.
But often time such campaigns are waged by former victims of trafficking. It's well documented that trafficking, prostitution and pornography are closely interlinked - this modern notion of a fully liberated "sexual worker" controlling their careers, choices and finance is substantially a fiction of the pornographic industry. So there is real merit în the anti porn stance.
Of course, once the camping is set in motion, it takes a life of its own, that has nothing to do with the concerns of the victims and more with prudishness; the religious circus will join hands and demand the removal of synthetic pornography etc.
Targeting them with what?
What could possibly hold enough leverage that Visa would jeopardize their sweet gig as an ideology-neutral, essential piece of American infrastructure siphoning 1-2% off of every dollar of consumer spending?