In many cases, the summaries are sufficiently thorough that I can discuss the work in question with people who've consumed it and not miss a beat. (This is a reliable tell regarding the work in question, and often of its fandom.) Letting others talk has done far more to tell me that I was right to go with the spoiler and skip it than to convince me otherwise. Using spoilers as a screen allows me to avoid most of the crap.
At first I was surprised by the title, but realized that dammit, I do the same thing, almost.
I don't go out of my way to find spoilers unless the trailers and marketing have social justice/message fic "tells", but I certainly don't go out of my way to avoid them. Good movies, stories, and shows bear rereading or watching (say, The Usual Suspects) even after you know the "surprise" twist. "Twists" in social justice crap almost always involve exactly what one would think even if the exact method or lines of dialog are open to different verbiage.
As Walker implied, the works in question aren't really that imaginative, and the stories and themes are far more repetitive than anything Ms Grundy or the church ladies would impose.
The most egregious example being an episode of L&O:SJW (more commonly known as the longest running fantasy series "SVU") where on seeing the trailer I predicted a) this would be the one time a guy was falsely accused of rape (because he's black), they wouldn't punish the women, and the old white guy who was his manager / whatever would somehow turn out to be the bad guy. How did I know? Repeat after me... because if there's a straight white guy he's somehow responsible for everything, and if it looks like there's a black bad guy, he's not.
But I'd argue that Dune, while Excellent, is overrated, and I'd instead put Mote in Gods Eye (I know, I know, YMMV)