the success of star wars has pretty much trapped him into doing star wars forever and no other projects.
kind of how roddenberry was trapped into being the creator of star trek,
or no matter how much j.r.r. tolkien contributed to philology he is only remembered for the lord of the rings.
even Joseph Campbell was trapped by fans who wanted him to continue to write hero with a thousand faces type books while he wanted to write about other things.
so as much as actors get typecast to a particular genre or character they play writers of books and directors and writers of movies do also.