It's not as simple as that, guys. There is a lot of imagination in Hollywood, but very little people willing to take a risk. Without the likes of Cameron and Nolan, neither Avatar nor Inception would have ever been made. It's only because they had Titanic and Dark Knight under their belts that they were allowed to get a green light. There are tons of talented people waiting in their shadows for a chance to express themselves. Alas, producers are extremely cautious these days. Because of the implosion of entertainment in the past 20 years, cinema has to compete to exist, which means that negative cost is usually smaller than P&A. It cost a lot of money to produce a film, and even more to let you know about that film. This competitiveness has pretty much destroyed independent cinema. So naturally, producers will turn to known properties, such as Arthur, were the risk is sustained. There is always a risk in this industry, but much less if you take a subject matter that is already in our collective consciousness. So don't crush artists, because believe me, they are dying to allow you a glimpse into their brains.
T