Fred Astaire: Can’t Sing, Can’t Act. Balding. Can Dance a Little. - Studio expert.
If you want show biz / arts mistakes...
E. T. Was passed on.
Harry Potter was rejected by nine agents.
Twilight was optioned then given up by Paramount.
Fox failed to secure any of the Star wars licensing rights.
Maybe they were right after all, though she could’ve killed herself without being famous I suppose.