I mean, I mostly agree with you. I don't think writers should pander to the changing whims of its audience; however, I also don't think the difference in audience reactions to GoT and The Sopranos has anything to do with changing whims or sensibilities. The Sopranos got away with it with little backlash because they handled the matter truthfully, despite the fact that it wasn't actually necessary for the plot.
In fact I'd argue that Sansa's rape was a lot more necessary for the plot than Melfi's. The writers didn't need to come up with a reason for why Melfi would continue being Tony's therapist. Cutting the few minutes of screentime they'd dedicated to that subplot prior her rape would've been a lot easier than what they ended up doing. In the end, Melfi's rape isn't an example of good writing because of it's relevance to the plot, but because the writers handled it truthfully and with a ton of thought and nuance. All of this was missing in Game of Thrones.
Whether it's necessary to the plot isn't the most important part here, nor is it offending the audience. The main point of those questions is to basically ask: are you prepared to handle this truthfully and thoughtfully? If the answer is yes, you will most likely be answering the questions correctly anyway.
Also, as a book editor: you wouldn't believe how many amateur writers include a lazy, unnecessary rape scene just to raise the stakes or show how bad a villain is. I've read so many of them by this point, it's absurd. So many of these writers either don't care about being truthful, or they think they're being truthful but aren't. Yes, most talented writers sticking to the maxim or "writing truth" will know the difference, but most writers aren't that talented, or even if they are, they aren't experienced enough yet to know the difference. My intent with this piece is basically to let amateur writers know that sure, you can include a rape in your story, but you sure as hell better put a *lot* of thought into it before you do.