Did mario puzo have a bad experience with a movie studio?

I’ve only read about four books of his but in the godfather and fools die the head of the movie studio are complete scumbags with no redeemable qua!ities …

I know he wrote for the movies for years but he seemed not to like anything associated with them and wondered if they were based on any specific person and experience…

I met Mario Puzo once. He was a miserable excuse for a human being. At first I assumed he was being an obnoxious drunk . . . but it turned out, he hadn’t been drinking.

Doesn’t look like it: https://en.wikipedia.org/wiki/Mario_Puzo

But lots of people have a jaundiced view of the snakepit of Hollywood.