Jon Stewart is clearly an unusual figure. He might have said, 'If you want me, you've got to have me on my own terms'.
The character of Annie Doultry is plainly a self-portrait of Brando. There are transcripts of conferences he and Cammell had, and Brando did a lot of improvising, playing the Annie Doultry character. Plainly he saw this as a part that he might play in a movie himself.