When most people think of a photograph, they don't think of it as something that consists of something built up of many layers of subtle nuance. They think of it as just "taking a shot".
When those people think of a painting, they are more likely to envision it that way.
Many of us here know that a good photograph can indeed be something complex, nuanced and multi-layered. And quite a few here know that painting can be simplistic.
I'm never offended when someone says something that shows they think of photography as a simplistic medium, although I am a bit surprised Sorkin didn't say "snapshot" rather than "photograph".