One of the reasons you get those threads on IMDB is because everyone thinks they've got a great idea for a movie... and they often think that idea is enough to get the film made.
As a screenwriter I've had too many experiences where someone has approached me to co-write a film with them... they have an idea, they expect me to write the entire script and yet they still feel that they are one of the "writers."
There is no shortage of ideas, just a shortage of good ones... and actually an original idea and a good one aren't the same thing at all.
The other reason people get so jaded about films being the same, is because audiences by and large go to see the same kind of films, time and time again.
If you watch Hollywood action films, then eventually you'll see they are all variations of the same story... but, there are a whole world of films out there which are nothing like that.
Audiences don't want truly original films, they want new twists on the same old story...
If they were interested in original films, it would be easier to get indie films with unknown actors distributed... but no, they all want the new Brad Pitt movie... and they want Brad to be pretty much how he was in his previous efforts (but with some new twist).
As a screenwriter I've had too many experiences where someone has approached me to co-write a film with them... they have an idea, they expect me to write the entire script and yet they still feel that they are one of the "writers."
There is no shortage of ideas, just a shortage of good ones... and actually an original idea and a good one aren't the same thing at all.
The other reason people get so jaded about films being the same, is because audiences by and large go to see the same kind of films, time and time again.
If you watch Hollywood action films, then eventually you'll see they are all variations of the same story... but, there are a whole world of films out there which are nothing like that.
Audiences don't want truly original films, they want new twists on the same old story...
If they were interested in original films, it would be easier to get indie films with unknown actors distributed... but no, they all want the new Brad Pitt movie... and they want Brad to be pretty much how he was in his previous efforts (but with some new twist).