Coming out of lurking to break down why that rape just wasn't necessary, from a writing standpoint. On the one hand, this world is pretty brutal, there are no deus ex machinas or shortcuts out, etc., however there were at least 4 factions/storylines converging on helping out Sansa and her Ramsey situation. There's Stannis and his ARMY, there's Brianne, there's the NORTH, and there's Theon and his exponentially building guilt. All four of these were written as just too late to stop a rape. Fair, whatever, the good guys can't always get there in time.

But then, there's the issue of character. Santa has already been sent through the ringer throughout the show, and she was given some sort of transformation both by the ending of last season and in the scene with Ramsey's other girl. So do we really need rape to make her even steelier? Gross, right? Redundant victimization and development. Don't need it.

Ramsey has also already been shown to be hopelessly evil, with so many heinous acts under his belt. We would be able to assume how this scene would play out. Goes back to the idea of rape as a shortcut to let you know that this guy is REALLY evil, discussed re: The Walking Dead. So yeah, this makes him superlatively evil, but we already knew.

And again with Theon, we've seen him broken down completely. This guy's been messed up and loaded with aforementioned guilt concerning the Starks. Did he really need to watch this scene go down to finally turn against his keeper? He's screwed up, we get it.

So with all that it's the writers who just wanted to make this rape happen. It was avoidable and didn't do anything new for the characters. Gratuitous.