It’s understandable. the film industry is rapidly declining and incredibly unpredictable. It helps to have some content with an already established fan base. Some of the biggest movies in recent memory (the first two “Hunger Games” films, the “Harry Potter” franchise, the “Twilight” franchise) largely succeeded because people were fans of the source material.
There’s something special about reading a passage or a paragraph or a novel. There’s something special about interpreting concepts, worlds, ideas and characters for oneself instead of just seeing it on a screen. Instead of watching the movie, read the book. There’s more to get out of it.