People are not blocked from being AAA movie stars on the basis of their gender.
Right, because they have the physical capacity to compete. In the NFL, the NBA, the MLB, etc., they don't. They just plain don't. If that confuses you then go take it out on God or biology.
If that is true why not let women try out for it?
Because at best it's a publicity stunt and wastes the time of all involved? Do you really think that a woman can compete with men on a football field? C'mon. Even the women in these sports laugh at the idea.