Last night I bought the second (or third) Blake Snyder book on plot and genre, Save The Cat Strikes Back, and in chapter one, while he's describing his "one line" plot descriptions, we come across this gem:
On the verge of returning to Earth after another routine mission, a rules-obsessed warrant officer lets an unknown alien species onto the ship; but when the creature kills one member of the crew and begins to grow in power, she must do what is right rather than what she's been told or else all on board will meet the same deadly fate. (Alien)
I read that and was flabbergasted: Dude, did you even watch the movie?
It isn't Ripley who lets the alien into the ship. Ash lets the alien into the ship. The whole idea of the "rules-obsessed officer" breaking quarantine is anathema to an essential tension within the plot. The entire point of the film is that Ripley was right to begin with. Ripley foreshadows the doom that comes to the Nostromo. Her words have weight. That's why she survives. That was a standard trope at the time, the girl who adheres to the rules is the survivor, and Ripley always followed the rules, down to her last log entry.
The best thing James Cameron ever did with Ripley's character in the sequel is make her a risk-taking rule-breaker. Because the moral values conflict between "saving Kane when you have everything to lose" and "saving Newt when you have nothing else to lose" is incredibly powerful and valuable and instructive, and this facile plot description completely takes away that sharpness of that contrast.