When intelligent sf geeks show how clever they are by going to extremes to point out cliches which, when used properly, can work, and probably did work well in their favorite movies.

Kind of like discovering that kissing and fondling are common elements in relationships, so let's avoid them like the plague.

Relationships with humans, of course...

This isn't so much a cliche as something that just alwasy struck me as dumb: No homing photon torpedoes on Star Trek!!! We have homing missiles NOW for God's sake, and we're aiming at planes that are a little bigger than SUVs, in ST they're aiming at ships the size of city blocks! Maybe they come up with them in later ST series, but I don't recall seeing homing torpedoes.

The other Sci-fi cliche is to have a character in the far future enamored with books, music, clothes or something else from the past that just happens to be relatable and/or recognizable to the audience so as to give the character a quaint little tag. But how many people in the 48th century are really going to be dressing in zoot suits and playing the trombone? And it's always the older, senior characters who do it, as if being 30 yrs older than the junior crewmen on a spaceship makes any difference when you're talking about hobbies that are 3,000 years old or older. The old guys weren't around in the 1940s any more than the young guys were.