Metafandom

Then there is the paradox in that if "the Author is dead" and texts are these independent things, why should the fanfic author expect their readers to "interrogate the [fanfic] text" from what they consider the "correct" perspective?

I don't believe I've ever encountered that opinion, sorry. I've seen a lot of the opposite opinion, i.e., if it didn't make it into the text, sorry, your intent doesn't really count for anything. Not so much of the "you're interrogating this fanfic from the wrong perspective!" except occasionally by people whining over people analyzing their fic and problematic racial or gender or whatever tropes in it (usually without either name or link to the original text so as to not cause a pile-on on the original author).

Could you give an example of this sort of attitude among Pretty Princess Monsters Blargh?

Why should the Pretty Princess Monsters Blargh care about the Scary Ponies Oh No interpreting the text using the "dominant" reading? Because the Scary Ponies Oh No are dupes of the evil "hegemony"? That Scary Ponies Oh No aren't capable of "analyzing" a text for "subtext"?

I don't particularly think we do. I mean, it's frustrating when you're trying to discuss, say, sexism in SGA or race in Doctor Who and the person you're trying to discuss it with keeps going on about how that wasn't the intent, why do you have to spoil their (his) fun, it's just a show, why do you care so much, why do you watch it if you don't like it, &c. It's even more frustrating when you're trying to discuss a problematic trope and people keep coming in and commenting just to tell you that they don't care. (If you don't care, get out of the way for the people who do!) But that's the same frustration anyone would have in the same situation.

Inasmuch as my post evinces some kind of caring on my part that Scary Ponies Oh No tend to interpret the text according to the dominant (PTB-approved) reading rather than any kind of more subversive reading even unto just seeing slashiness where it wasn't supposed to be--I certainly don't want to give the impression that I attach any kind of moral value to anyone's interpretation or interpretation style. There's a time and place for everything; certainly a community meant for squee and celebration of a text on the text's own terms is just as valid as a sporking community, or serious meta community, set up for the same text. All fannish reactions are acceptable! I do think there is value in examining texts critically, especially while paying attention to handling of race and sex and gender and so on, but such a reaction can and often does exist side-by-side with less critical reactions, and certainly not everyone has the (tea)spoons necessary to examine every piece of entertainment and pop culture the media sling our way. Gods know I owe every piece of my readings of Harry Potter to the smarter people at Snapedom, on Snapecast, on Harry Potter For Grown-Ups, and elsewhere around HP fandom and Snape fandom in particular.