My bet is the furries. You don't have to think hard on the excuse why - the finger-waggers will gripe about how it promotes bestiality or the likes. And unfortunately for the Fur-suits, the unhinged side of their base produced enough ammo over the years for a target on their backs.

Of course, it doesn't necessarily need to be restricted to our weirder sides; it could also be a political target, too. Don't forget, the ADL has spent years screeching about Pepe memes (not actual Nutzi propaganda, just the silly/bad joke memes). Kiss your silly-but-harmless avatar goodbye once the ADL meet their contact in Visa. (For a bad laugh, look up why "Anti Defamation" is in the name.)

Regardless, I am certain of this much - the payment processors WILL be back, with a new list of games that another shady special interest group wants gone.

That's how it goes - start with small controversial stuff that few people will personally defend, then chisel away piece-by-piece towards bigger, less controversial subjects. This isn't the first time the credit card companies attacked - look what happened to Gumroad for example.

Will it affect my games? I don't care. I'm not going to stay quiet until it does and there's no one left to speak for me. The excuses for bans and censorship are complete BS. Video games do not create bad behavior in themselves.
I've heard the opposing trash takes before, in the form of 'violent video games create murderers.' Tell me, how did that conjecture work out?

We already have an adequate censorship program - it's a simple one-step process called DON'T-BUY-THE-GAME! If anyone else can directly or indirectly tell you what legal transactions you can make, then whose money is it really?

I understand Valve as a corporation must constantly balance such matters to minimize their troubles - but appeasing the Credit Card overlord is a massive blunder in the long run. It's like slicing off your finger to appease a hungry shark, bleeding out in the water and attracting more sharks. You are just gonna git bit harder next time.

Perhaps Valve indeed should explore payment alternatives - at least for its own services, to regain the control that the likes of Mastercard just seized. Yeah, it's complicated and likely costly, but if there's anyone able to accomplish this, it might be the corporation that deploys a billion-dollar international gaming platform.

If all else fails - seek alternatives yourself. Those who care should do so before the game you love gets hit. If you don't figure it out and it happens, most likely without warning... well, you're being warned now.