For the lack of good scripts
There is a saying: "The script is the root or foundation of a film". In fact, the Chinese word for script is juben, which literally means "source of drama".
As such you'd be forgiven for thinking scriptwriters are held in high esteem. But scriptwriters are near the bottom of the entertainment echelon, somewhat higher than the nameless extras milling around, but rarely close to the power center of directors, producers and stars.
A friend who is trying to get into the field told me the standard price for a film script is around 100,000 yuan ($14,682), but you get just one third in advance and should not expect to be paid in full, as others, including the director, will chip in, make revisions and turn themselves into co-writers. You will be lucky to keep your name in the final credits.