I’ve found this to be true. For example, a typical “House” is mostly about the medical mystery (roughly 2/3): what is the disease doing and how do we cure it?

The other third is spent on character exploration and ethical and thematic issues.

However, in the pilot, the proportions are reversed. Although the medical mystery drives the story, much more time is spent on revealing character and their point of view.

I suppose you could generalize by saying that the pilot is a tool to sell the characters more than the story.