Ideas for new movies ?? Way back when I was a young'un I took a college cinema class and learned that there are only 4 topics/themes/concepts for a movie. That was the opinion of the instructor, as he explained that is why you see the "same old movies" over and over, only different because of the actors and set designs and basic dialogue.
Even though a source as new, up-to-date, impeccable, & unimpeachable as "the internet" will contradict that number of 4, the instructor would probably explain that audiences only want to be entertained by a couple of themes, and may tolerate a couple more. Most audiences don't want to think. Or if they do think, it's not deep like a well. And of course, that industry is profit-motivated, thus a movie with profit potential is more likely to be made.
So within those constraints one would/should expect to see "the same old theme(s)" rehashed again and again ......
(for some post-graduate reading on Central Themes:
http://www.storytellermark.com/newslett ... n_film.pdf )