Dr Who attracts autists of all the rainbow spectrum because it is autistic, especially the reboot.
It had been always zany, illogical and nonsensical most of the time, but lately it had jumped the shark with just how stupid its story had gotten.
There is also the problem with the show that most shows get a season per year. Dr Who is a bit slower, which makes it harder for viewers to stay connected to it, unless they are the aforementioned autists.
It fucking had the moon being an alien space dragon egg. You can't get more retarded than that. The timeline all blurs into a big, spergy-wonky mess where you can't even remember all the stupid shit this show had done, and that is for the best.
So in the end, what the doctor is no longer really matters. Most of the time, the character does not at all act like a centuries old wise alien any more. Whenever the doctor has tits or no is really only that much interesting to autists. But I doubt it can reverse the sharks jumped by just how stupid the plots had become. The good point of the 12th was that he was a grumpy old guy who actually did manage to act like a grumpy doctor at times. Will she be able to be just as grumpy too? Time will tell.
The only way to actually save the show in the long term would be to fire the entire writing cast and get someone totally new who knows about storytelling and at least has a basic understanding about science. A Dr Who episode where you could follow the plot without facepalms or getting drunk would boost the rating better than pandering to any side.
Why the crumpets does he even regenerate into some type of brit all the time? He is an alien from space! Man or woman, sure, but why always a brit?

It never made sense to begin with.
Though.... I have to agree with Vox Day. A black male Wonder Woman is super progressive and would be totally lolworthy. Who says black men can not be wonder women? Transmysoggykneeraycisssts! Are you denying their gender and oppressing them because they are black?

He is a proud princess!
Radfems would ree for troon. Racists would ree for black. SJWs would ree because the actor is dirty cis male. The whole internet would melt down.
It would create such a salt storm that we kiwis would be very well fed and the Atlantic would be saltier than the Dead sea by the time the reeing stopped.