Man there is way too much group think going on here. I'll go ahead and play the contrarian, because I think the issue here is being marginalized on this board, and it deserves a bit more respect than that.
The issue here isn't the rape. The show has portrayed rape before, and it will likely portray rape again. Had they followed through with the Jeyne Pool storyline, I imagine there'd still be a great deal of outrage, but when you start orchestrating some sort of double-rape with a eunich and beastiality, you'll raise a few eyebrows.
The issue here is Sansa, or more particularly, Sansa's evolution in Martin's universe.
I brought this up probably 200 pages ago, but my wife is working on her doctorate studying females in fantasy novels, specifically focusing on the gender roles and sexual identities of characters in Tolkien's world vs. Martin's. (As they have arguably built the two most complex and epic worlds, and exist on two very separate spectrums. (Some of it is absolutely fascinating, like Samwise Gamgee filling the role of the traditional wife, but that's way OT)
What is relevant here is how Martin builds out character development. All of his characters follow the same baseline goal, whatever it is for their character, until that course of action fails them. At that point, they are either forced to adapt at the cost of some extreme physical or emotional impairment (see: Bran, Jaime, Tyrion, Sansa, Arya, Jon, etc.) or die (See: Ned, Robb, Catelyn, Joffrey, etc.) In a Proustian sense, characters can only grow and develop through adversity.
How is that relevant here? Well, a few things are at odds: For one, none of the major power players are acting in a way that makes sense for their desires. Sure, Ramsay's claim to the North is a bit stronger with Sansa as a bride, but at what cost? Would the Bolton's be so quick to alienate themselves from both Stannis and the Lannisters, his one and only powerful ally backing his claim? And why would Littlefinger go through all the work to capture Sansa only to leave her at Winterfell, so he could make a claim on the North himself? There'd be many other ways to accomplish this without forfeiting such a powerful piece.
But most importantly, after all Sansa has been through and survived, after all the growth she has gone through, would she so absentmindedly walked into this situation without any preparedness? It would be a worthy debate had Ramsay portrayed himself as a proper gentleman until revealing his colors on their wedding night, but that's not what happened here. Instead, she sees all the warning signs; she knows this man is a monster. And she's given a way out, but instead unwittingly walks into this horrible situation so the showrunners could provide Theon with a moment of clarity. They absolutely needed to find a way to provide Theon with that moment, but not at the expense of another main character acting as a plot device.
Sansa should be evolving along the lines of Petyr Baelish, or becoming the next Olenna Martell. She is learning how to read people, how to keep them guessing, and position herself in a place of power. This scene served Sansa nothing but to strip her of 4 previous seasons of development.
Now, am I saying the show is broken, or can't recover? Absolutely not. I do think the show was a veritable masterpiece for its first 4 seasons, and just now is the quality between the books and the show starting to show through, but there are other issues at play besides the Sansa debacle. Dorne is a mess, and they should have stuck with the original script (or, if unable to do this, scrapped it altogether). This Jaime storyline and the half-assed attempt at the sand snakes serves no good purpose. Also, turning the most progressive government in Dorne into a simple patriarchy is just lazy. Considering a few of the last words Oberyn said before his death are "In Dorne, we don't hurt little girls!" it seems an odd choice for his daughters to plot the death of a teenage Myrcella.
The church acting as a power serving the far right seems to be done solely to appease the American fanbase as it's how Americans expect a religious entity to act. Yet in the books, the movement comes from the far left, which makes far more sense given the circumstances of the people in Flea Bottom, but the showrunners apparently didn't trust the viewers to understand how an extreme leftist movement could become violent. (See: Bolshevik revolution)
I just get the sense that so much of this show's reception was built off of trusting the audience to be smart enough to follow the intrigue and twisting plots, but here in the 5th season there's some rush to dumb it all down and streamline the process. I'm not sure who that serves, but it's no longer doing great justice to the novels. Whether that actually should matter is another debate entirely, but yes, I'd rate the Sansa rape scene as the worst misstep the showrunners have made thus far. It doesn't mean I'll stop watching, or Sansa can't be "redeemed," or anything of that nature. But it could certainly have been handled much better; main characters need to act with their own agency, they shouldn't be marginalized as a plot device.