sexism
Hollywood has always been something of a boys club. If you think about the golden era of the studio system, you always hear about larger-than-life stars and the maverick, alpha-male directors that made all the classics we know and love today. Think of pictures of giants such as Howard Hawks, Samuel Fuller, John Huston, or Alfred Hitchc*ck, who are usually seen dictating their vision with booming authority.
Grease has been hugely popular ever since it came out in 1978 – yep, it’s already that old. It’s rated 7.2 on IMDb and 70 by MetaCritic, and if you look on the IMDb message boards for Grease, for instance, you can see it’s still being discussed actively.