Sam wrote a post about the sorry state of Hollywood.
I would wager that it is less the quality of the movies and more the station you are in life. At one point in life, every idea seemed fresh and original (even though they weren't). We look back longingly at those days as the days of creativity (when they were actually also viewed as creative regurgitation by others older than us).
Hollywood is doing what it has always done. They make a few good movies along with a bunch of crap. At earlier points in our life we were bamboozled into thinking the crap was creative. Whether the source material is comic books, a novel, a video game, or an original screenplay is pretty irrelevant. None of it is original. Nothing can be original; it can only be done well.
It just sucks getting old and realizing that there is no such thing as originality, although there are people out there who are like we were when we thought regurgitated material was original. Oh, the humanity.
Now we do the same thing with ideas although none of them are original. They are just new to us.
