The lesson of the chaotic chart above, as Cory Doctorow of Boing Boing observes, is that Hollywood studio executives could make equally rational choices about what movies to make simply by rolling dice. They have no consistently reliable knowledge or instincts about what audiences want to see.
A relevant list of box office earnings over the years expressed in real dollar amounts shows only one film made in the last quarter century among the top ten -- Titanic. That's doubly instructive since Titanic, a film about commitment and female empowerment cast in the terms of a Victorian melodrama, violates almost every tenet of the current Hollywood wisdom about "what audiences want".
What's going on here? Hollywood executives aren't stupid, the corporations who employ them are presumably interested in serving their market. I think that Hollywood has simply given up. It senses that it will not be part of the future of entertainment but it lacks the energy to remake itself for a new age. Executives are interested in making as much money as possible in the short term by releasing the safest product they can imagine using the outdated paradigms and then retiring in style. After all, if all your peers in the industry are just as clueless as you are, as the chart above seems to indicate, then you have no real competition. What incentive do you have for taking chances?
[Note: The Birth Of A Nation almost certainly belongs in the list of the top 100 box office champs linked above but at this point there's no way of ascertaining exactly how much money it made. The film was released in most parts of the country on a "states' rights" basis, which meant that a distributor bought the right to exhibit the film in a certain territory for a fixed sum and then kept whatever profits he earned himself, with no obligation to report them to anyone else. Louis B. Mayer made his first fortune distributing the film in New England -- then helped create the Hollywood cartel which virtually monopolized film distribution in America, assuring that no new entrepreneurs could ever again make money the way he did when he was starting out. This illustrates the basic principle of American corporate capitalism -- "Free market for me, rigged market for you."]