Earlier quoted context omitted.
I feel as if it's the exact opposite. Do any of Asimov's books on "positronic brains" hold up to genuine, in-depth scientific inquiry? He just glossed over the details of their workings. Does this mean they're not sci-fi?
It's not the setting that needs to be scientific for a work to be SF, though, but rather the conflict . The conflict in the Robot books isn't about "positronic brains," it's about robotic interactions with humanity. The science being employed is sociology. To put it another way—the initial state of the universe when the book starts can be anything you like, with any rules you like. SF is just a strict dedication sett…
Perhaps in the case of Avatar, the science would be anthropology with a small bite of psychology and history mixed in.
A lot of good sci-fi stories gloss over the details of several sciences (and often violate them in ways that would make a screenwriter turn red) to have the opportunity to examine one specific idea.
Or, to put it more concisely, they tell one story while pretending to tell another.