Short reason: for not the first time, GoT is using rape and abuse of female characters as a cheap drama trick. When that's virtually never the right direction to go, and almost always the utterly wrong way to go (which it is here, by all descriptions).
This tendency of "hmm, we're hardcore and realistic, someone's gotta get raped" is one of the most pernicious and vile concepts in so-called entertainment. I have never had a major character go through that, and offhand I don't think I ever will. I've had two close approaches (in Madeline Fathom's backstory, it's clear what the cult leader intended for her, and in Phoenix Rising, it's also equally clear what [SPOILER] intends to do to her) but in both cases it goes nowhere and those involved get exactly what they deserve.
We're writing fiction. We can choose to make our world a BETTER one than the one we live in, and we have no excuses of "realism" if we're writing fiction. We get to make the rules.
Alas, this concept is pervasive to a degree that is almost ungraspable. Witness the time someone asked Seanan McGuire when one of her female characters was going to be raped. Note, not "IF", "WHEN"; it was an assumed inevitability that such characters would eventually be raped, and some people in that linked article even argued that it was REALISTIC. I am incapable of properly expressing the level of enraged jawdropping that this assumption causes in me.
For the record, my characters (male and female) are not going to be "developed" by this vile and cheap mechanism, and I would hope that any other authors out there who read my stuff would seriously consider not going down those roads either.