So what about those screenplays that your friend working at the video store is constantly writing, in hopes they will some day get made and star a naked Natalie Portman? In reality, even the great ones are treated as spec scripts (basically, a literary audition). The script is proof to the people in charge that the writer is, for the most part, not illiterate. So if you submit a powerfully emotional piece that deftly explores the facets of love and loss, you might impress someone enough to get a job co-writing Transformers 4.
On the rare occasion that an original script does get picked up for production, it's likely to get swept up by one of the big franchises. I, Robot was initially an original script called Hardwired that no one would touch until a famous Asimov title was attached to it. Die Hard 2, 3 and 4, Ocean's Twelve and Starship Troopers were all original ideas that were snapped up and rebranded as franchises. So if you're working on a passion project, maybe it's time to let the dream die and just start focusing on a gritty reboot of She-Ra.