A Woman as the Doctor
With Jodie Whittaker announced as the Doctor there have been a variety of reactions. This isn't too surprising - pretty much every new Doctor announcement has been met with reactions ranging from "this is the perfect Doctor" to "Doctor Who is ruined".
Unsurprisingly, the fact that a woman has been cast as the Doctor for the first time in the 50+ years of the show has a higher percentage of "Doctor Who is ruined" folks out there. It's definitely a big change in casting. I recall Usenet discussions in the 1990s about a hypothetical woman Doctor - and it should be noted there were people who questioned whether there could even be a non-white Doctor. Similarly, as the cast of Star Trek: Voyager was announced, some people went a little nuts at idea of a black Vulcan - Tuvok, as played by Tim Russ. It's worth noting that for me, Russ was one of the bright spots on what I saw as a fairly mediocre show. (I also greatly like Kate Mulgrew as an actress but found her character of Captain Janeway was inconsistently written).
So what about a lady Doctor? Well to begin, my daughter Jasmine was quite happy at the announcement. She's the science fiction fan of my two daughters. Her sister Victoria is passing familiar with Doctor Who and she was pleased too. There's something to being able to imagine yourself as the hero - and the Doctor is a great hero. Not using guns but his (or now, her) brains to fight evil. Sure they could someday to a spinoff with characters like Jenny, Clara, and Ashildr/Me. But Doctor Who is the core of a decades old institution.
Were they being social justice warriors? I don't know, and you know what, good on them if they were. I hate the use of that as an insult. It's great to have greater inclusivity and Doctor Who is a show whose format greatly lends itself to such a casting. Every few years a new actor takes over the role with no expectation of a resemblance in appearance - indeed the Doctors all look very distinct from one another and you'd never mistake one for another. The new show has clearly established Time Lords can change gender. Yes that's an addition to the show's mythology, but it contradicts nothing. And let's be honest, contradictions in Doctor Who are nothing new. Michelle Gomez's portrayal of a female Master, Missy, has been.. well, masterful. A homicidal Mary Poppins.
I can think of a million in-universe reasons why the Doctor has been male all this time and now has a female incarnation. It could be some Time Lords are more predisposed to a single gender and with a new cycle of regenerations the Doctor has changed. It seems Time Lords have some control over the regeneration process (the Master especially) and since the Doctor generally thought of himself as male, chose to stay male but has decided on a change. It could be a gazillion things.
What about Whittaker as an actress. Truth to tell, I know next to nothing about her. I've never seen Broadchurch, where she had a major role. It's one of those shows that has long been on my "to watch" queue so I imagine I'll get around to viewing it. Given new Doctor Who showrunner's Chris Chibnall's roles in the creation and production of Broadchurch it's clear that he has an actress whose work he is familiar and comfortable with, meaning it is quite likely the two will work well together to realize his vision of Doctor Who. Will it be any good? Will Whittaker? Time will tell. I hope so.