I thought this was interesting, from his autobiography Did They Mention the Music:
“The albums were made up of the most melodic material from the films. A lot of the dramatic music – which is what I really loved to do and really thought I had a feeling for – was left out … I used the source music that was the common denominator for my record-buying audience. It may have hurt my reputation as a writer of serious film music. To this day, I would love to have an album of some of those scores as they were heard in the film. The albums gave me a reputation, even among producers, as a writer of light comedy and light suspense, and at that time it was not easy for them to think of me for the more dramatic assignments. I did that to myself.”