The reason Americans don't care about prison rape--in male or female prisons--is that Americans don't care about prison or prisoners. We jail more than any country in the world, including China and North Korea, who jails entire families, but we don't actually think about or care about prisons. They're poorly run shitholes where we toss people we want to forget about for a few years. Prisons aren't meant to reform people, they're meant to punish them. Not for justice, but for vengeance. Society feels wronged and it's response to that is to abuse and demean the guilty party for the rest of their lives, slapping them with a criminal record and forcing them to deal with the consequences of what might have been youthful indiscretion, or something that they now regret and feel shame over, forever.
Prisons are places we put people to forget about them. How they're treated in prison is part of the punishment. Rape, abuse, being stabbed to death? Americans see that as just the purpose of prisons. I mean, look at how we talk about it. "Federal pound me in the ass prison"; Watch Law and Order enough and you'll see the cops threatening the criminals with prison and detailing how they'll be raped and/or murdered. One of the reasons I stopped watching SVU is because they'd constantly be threatening this mentally handicapped killer or whatever with descriptions of how they'd be shanked for murder or rape if they didn't confess, as if the gangs in prison were some unofficial deputy of the prison system, carrying out justice. And no matter how much it looked like Stabler was going to learn a lesson about not psychologically torturing people who were showing fear and confusion instead of guilt, it never did.
That's how our shows go. That's how society treats prison violence of all types. If anyone talks about how much better Northern Europe's prisons are, with computers and little two room dormitories, it's to say how touchy feely those Euros are, and how their prisoners must commit crimes just to go to those fancy hotels. We don't want to treat prisoners like human beings. Then we'd have to acknowledge that they are human beings, and we'd feel bad about joking about their rape or murder. We'd feel bad when we see a criminal in the news and say how we hope they get what's coming to them in prison. If we admitted prisoners were human beings we'd have to have empathy for even the worst of them. And people don't want that.