A writer writes not because he is educated but because he is driven by the need to communicate. Behind the need to communicate is the need to share. Behind the need to share is the need to be understood.
The writer wants to be understood much more than he wants to be respected or praised or even loved. And that perhaps, is what makes him different from others.
Action, reaction, motivation, emotion, all have to come from the characters. Writing a love scene requires the same elements from the writer as any other.
I'm fairly competant as a director and actor, but I am Mr. Neurotic as a writer. I just don't have enough confidence in my abilities to take criticism well. I take it personally. Start with 'It's a masterpiece,' and then tell me what you think could be changed.
That process by which you become a writer is a pretty lonely one. We don't have a group apprenticeship like a violinist might training for an orchestra.
Stephen King in many respects is a wonderful writer. He has made a contribution. People in the future will be able to pick up Stephen King's books and learn a lot about who we were by reading those books.