Some novels, because of their structure or dialogue or the premise, make excellent movies. A lot depends on the director, screenwriter, actors, and the others working on the project.
A writer-turned screenwriter would have no control over anything, even the final version of their own screenplay, unless they were already very powerful like the case of J.K. Rowling and the Harry Potter books. She had control and she didn't even write the screenplays.
Nothing wrong with an author wanting their book turned into a film or tv mini series. I wonder how many screenwriters dream of their movie being turned into a book?