I've played it, and without spoiling, there's no way to play it through and come to the conclusion that the rapist (and mass murderer) is an even halfway decent person. It's not titillating (not that the graphics or art style would allow for that in any case), and it's not played in any way except upsetting and mature.
Tbh it's a pretty impressive narrative experience, it really leverages the difference between watching a story and experiencing it.
I doubt I'll ever play a game like that, but it does sound reasonable for a game like that to exist. Especially in light of the horror and violence we do allow. (Didn't GTA require you to torture someone? I know people who refuse to play it only for that reason, yet I don't think it was ever banned.) Of course I wouldn't want games that celebrate and glorify rape, and wouldn't really object to seeing those banned, but it's always hard to draw the lines with bans like that.
I recall some years ago that bans on sexual content for teenagers also ended up banning sex ed content, info about contraception and other vital information.
So I'd really prefer to err on the side of less rather than more bans. No blanket bans just because they address some topic, because some topics do need to be addressed.
Ultimately, though, I really don't think it should be up to payment processors to enforce stuff like this. It's up to either Steam or governments. If payment processors want to police stuff, they should be concerning themselves with money laundering, fraud, and other financial crimes.
It's definitely one to play when you're 100% up for it, and I'd argue it might even be best played with other people. It's genuinely rough, but impressive as hell, and it's a great example of people making their vision come to life with pretty simple tech.
Tbh it's a pretty impressive narrative experience, it really leverages the difference between watching a story and experiencing it.