Movies influence others to become filmmakers, naturally. Conversely, people, human nature generally speaking, influence movies. If they didn't, we'd never get great movies that delve into the psyche of serial killers and the like, which I always find fascinating.
It's my observation in the Star Wars realm that the films didn't necessarily *influence* anyone, but it's "the movies we grew up with" debate for so many people, which explains their loyalty to the brand through thick and thin. However, there are a lot of great messages that could be taken from "Star Wars", aside from incest.
I wont talk about the negative influence of films , guess we all know them.
However, If movies have some meaning & message(not just entertainment), I think it definitely gets through.
When we see some character fighting against all odds & who is a positive, compassionate human being, people do remember such heroes in their own difficult times.
I've personally felt motivated to do more positive things after I saw a movie character do so.