My wife told me that you would not believe the amount of really good ideas pitched to both the TV and Movie divisions. They even have a pitch day for employees where you can pitch any idea you have. The problem is that when they hear a really good idea, it is reworked and reworked endlessly until you the final product -- generic fluff that is as far away from the original idea as Pluto is to the Sun.
Hopefully, this year is the beginning of some changes. I heard there's a Maricel mystery-thriller being worked on and there is talk of following the Korean/Japanese tradition of just doing mini-series type of shows.