I also wrote a script about Dragonheart 2, then, it came out as a movie. This movie was a childish disgrace upon the original. I had a couple friends read the one I wrote(but never sent) and said it was hundred times better than the version that was shown&I should have hurried, that some one just simply beat me to the idea. 
I then wrote a script about King Arthur, the historical one, not the fairy tale&I think it was pretty damn good. But, I was so discouraged I threw it away after a TV-Movie about the king came out, then the next year the screen version of last year came out.I guessed probably it was a flood of scripts about that subject just gathering dust on producer's shelves in Hollywood. So, I gave up my dream. But, it was not a waste of time--anything that give you any kind of skill is no waste&at least I was not watching soap operas, now that's a waste!
Also, I enjoyed writing&although definitely no pro, it did releive stress&kept my mind from turning to butter, so I feel anything that keeps your mind from becoming stagnant is good, even if it is non-profitable.
However, even today I watch some movies or TV shows, shake my head&think,'Damn--I could have done better than that!"
It would be cool to read the one about the cult and mass suicide...
It would be cool to write a good movie, but doing that writing stuff as a hobby made me realize those movie writers don't have it so easy perfecting their art--in fact, I think they have a harder time than the actors. Also, I learned most writers do not get paid well at all, unless some BIG movie company buys the script, or it turns into a blockbuster. There are many starving writers out there!