It seems pretty clear to me that we should create our own group to counter things like this from happening.Well they're anti-violent things too. Long before they turned their eyes towards sexual content, there were already decades of global action against civilians owning weapons and limiting what is construed as self defense. In most countries around the world a person who defends themselves against a criminal will get more prison time than the criminal.
Even here in the land of cheeseburgers and guns, we had stuff like Operation Chokepoint with payment processors trying to shut down website hosters to gun stores/forums, and associated transactions.
They kind of lost that war due to CAM such as 3D printing though. 3D printed weapons are good enough that they are used in every major conflict in the world today in some form. Eroge needs to undergo a similar revolution of self sufficiency. Personally I think crypto currency is that answer. We already have a lot of options for distribution of the games, once an alternative payment is established they really can't cancel anyone that easily. F95 and similar sites are already good for indexing and finding new games. Frankly better than Itch IMO.
You mention guns and they have their support groups who still seem to be pretty successful in defending their rights.
And i agree we need to find a way to pay without having to rely on the big payment services since it's pretty clear that they have way to much power and are to easily influenced by others.
With crypto i have some doubts tho it's seems to easily influenced by price fluctuations and we would also have to avoid the coin being associated as "the sex coin" or the "erotic game coin" since that might make it harder to get that coin.
The last thing i would like to mention is that we need to find a way to counter this group or groups that arranged this it's clear they have gained to much influence but since they target other things as well besides erotic games they probably have a lot of enemies.
Maybe we should try to get into contact with those enemies and see if we can find a way to work together in countering this group.