Because once something is "in a movie", then any attempts to bring it into the "real world" are mocked more easily by saing "yeah we saw that movie too, blah blah, get with reality you dreamer"

Its not much different from 8 mile where rabbit makes fun of himself so the other guy has nothing left to say.

See, we use the movies to explain - which steals the originality or authenticity of the thought and robs it of its power to inspire action. People can just watch someone else do it and then they don't have to do the work. They think that since they are not the hero in the movie that they can't achieve the same things, even if it is right and true.