1. Easy Money
I think all my other points have proved the point that not making a Quidditch movie makes no sense. This is such easy money for Hollywood. Warner Brothers would be stupid not to exploit all HP avenues; they have a built-in international fan base - you see that logo, hear that music and you instantly think of the Harry Potter brand. The bottom line of a film being made is: Will it make money? How much? Does the franchise already have a built-in audience? How much marketing will be needed? It's not unusual for the marketing budget of a film to be up there with the production costs. More and more studios are gambling less and less on new material, which is why you're seeing so many sequels, prequels, spin-off's, comic book characters - anything that already has a platform, an established brand. A big question pondered in the executive offices - Does it have potential for merchandizing, video games, tie-in's at fast food places? The ability of a film to make money on the back-end is crucial in this age of movie pirating and lower cinema attendances. Being a sport film, we can presume lots of heavy action and fairly light on the dialogue, therefore few sub-titles would be needed compared to a hard-core all talking drama. That is important when going after the Asian markets. So - Warner Brothers - let's get a good script, cast it well, don't cheat the audience and you'll have a box office hit with Academy Award nominations in many categories...go for it....I dare you...