If you can fin a thread in which I categorically dismiss a genre as "drivel," please post a link. Of course, strictly speaking, film music is an application and not a genre.
Henry Mancini wrote about opening doors for Quincy Jones. There was an assumption at the time that black composers should score "black" films. They were reluctant to have him compose for strings, for example.
At any rate, Duke did Anatomy of a Murder, and Count Basie wrote the theme to M Squad, so things were starting to change.