So, the consensus is that we should just say and write "weird shit." This is good marketing practice, because some readers and viewers are temperamentally unsuited to that kind of willing suspension of disbelief, while others are. Sounds like a good idea, we're all creatures of mass commerce.
And, to uphold mass commerce against the vile prescriptivists, we should insist scientists stop obscuring communication by misusing the word "theory," which has long meant "personal opinion." And "materialism" would just mean "greed" (but not "avarice."

) And so forth.
Obviously science fiction criticism isn't of great importance (as opposed to possible interest) but also obviously the refusal to even engage the subject is, well, "obscurantist" is the word that comes to mind. But pardon me for lapsing into the old prescriptivist language. I think the official phrase is "blowing smoke."
The people who like to cite Damon Knight's definition (and those who like Norman Spinrad's, too) are rarely,
if ever intested in troubling to point, much less discuss what they point at, or in discussing marketing (advances, maybe) either. The tacit assumption skiffy stuff's in nothing but stupid stuff fit for the slumming mind only has its complacency to recommend it. No, if you intend to criticize, excuse me, "chew over" SF, taxonomy is essential. It's essential to biology, how is literary criticism superior?