Einstein was a really interesting guy. He wasn't some dutiful little chap who went through the academic system and did everything proper. He had an enormous ego -- any lesser ego would have given up. He publishes this stuff and nobody pays attention for four years, but he is possessed -- and that's what makes him hell to be with as a human.
If you're writing about one real person in history, you can soak up that person as a human, collect all the things you can gloss over in a documentary. But to balance five or six of them, there isn't time to do justice to each character. And if you get too heavy on the science, you'll lose the audience.