@darekpawlo Seems to me he's an extremely pessimistic person. Thought that basically his father was using him, so when he started supporting him, he considered the one ambition and passion he had was taken away and being driven forward by his father. The father probably made a lot of choices for him and didn't give him a lot of freedom in things like which college he went to. So they guy probably saw it as his father planning his life for him and that he didn't have control over his own life.
He lost his motivation to write because his dad became his editor and he lost control of the stories he was writing. Instead of being an outlet for his creativity, it was his job.