You have to live in order to have something to write about - you get caught up in moviemaking and celebrities and money, and it's very intoxicating, but it doesn't give you what you need as a writer. You have to do something else for that.
Playwriting is the last great bastion of the individual writer. It's exciting precisely because it's where the money isn't. Money goes to safety, to consensus. It's not individualism.
I've been writing plays since the seventies and only came to moviemaking when I basically realized that I needed some money to pay the rent. I started to watch films with an eye to figuring out how to write them.