It's already been said in this thread, but Perlmutter is probably the biggest reason there's no Black Widow movie. The same Perlmutter that once sent an e-mail to Sony about how unsuccessful female led superheroes have been over the past 20 years. The same Perlmutter that, more than likely, said Mya Hansen couldn't be the primary villain for Iron Man 3 because they needed to be able to sell toys to kids.
And as far as females directing action blockbusters, while Wonder Woman was an important step, we need to move beyond the idea that women directors being needed to tell women's stories, and realize that they can tell men's stories as well. We shouldn't be stuck in a place where the only time women get to direct action movies is when there's a female lead. My personal hot take on the issue is that if Jenkins had stayed on and done Thor 2, and it had been good, it would have been better for women directors than her being successful with Wonder Woman, because it would have shown that the story doesn't have to be focused on a woman for a woman to be able to tell the story (which should be obvious, but then again, this is Hollywood).
Edit: Also, even with the success of Wonder Woman, WB/DC has two other female led comic book movies in the works, and neither one is currently being helmed by a woman (Whedon and Batgirl, and I believe Ayer is still attached to Gotham City Sirens).