Blue_Wes
Simple Minded
People were ****ed off about the Jaime and Cersei scene as well, and that did nothing to advance any story, so I think it's also fair to assume at this stage that the Sansa rape is yet another shock tactic. Why not just end the scene when Theon was made to shut the door.
With Dany from her rapes she ended up being a relatively strong and independent person (still a pretty bad leader). That's a dangerous trope to play because it leads to the idea that women can be stronger after a rape. It might be the case in some examples, but on the whole being raped devastates someone's whole life.
The Joffery bits really did develop his character. He went from a **** to a complete misogynistic psycho and sociopath. He also got his just desserts.
With Ramsey we already know he's pure evil. We also know that Theon is regaining his 'theon-ness'. With Sansa she regained agency by squaring up to Melinda(?) and at the end of S4 as well. She had gone from a pretty weak and uninspired character into someone who was potentially ready to play the game herself. But that's been taken away from her.
I really hope Sansa does get the opportunity to recover. I don't like the idea of her spending the whole show being a victim, it seems unnecessarily cruel and pointless.
But I guess (yet again) we need to wait and see where the story takes up. Let's hope they've learnt a little from the pointless violence against women in the past and realise that people will only accept it up to a certain point, it needs to have meaning within the story, and it's easy to slip into clichés and tropes.
Anyway tl:dr
Jaime and Cersei was absolutely to progress the plot. It was the start of their rift whcih see's them fall aprt from one another. Cersei despises him now, and forces him away. Meaning she has no guidance and is all alone to make the rash impulsive decisions which will surely see her fall foul of the Sparrows. Jaime has now gone on a fools errand to Dorne, in a desperate attempt to save Myrcella and to try and win back the favour of his sisater/lover. Again, the implications of him (a Lannister) being found in Dorne could be huge.
I agree it doesn't need to become a theme. But it's a vicious world they live in, one in which everyone is trying to gain the upper hand; sadly in the only real reference we have to an era similar to the one's we see on screen, is deep in our history, and that suggests men did exert their power over women in this way.
The difference in the fictional world, seems to be that a lot of them come back stronger for it. Again I agree this shouldn't be the only way woman grow. Some in fact, use it to their advantage - I'd forgotten Melisandre earlier.