A) Suspension of disbelief.Mcoffey said:A) Martha seemed to do just fine taking charge in Shakespeare's London, and Depression-Era Manhattan, and it is a show and they could do whatever they wanted (And often do) to make it work.
B) That is a non-answer that goes back to "I fear change".
C) Diversity applies to everything because the planet Earth is a diverse place.
D)Moffat's run has been a shadow of RTD's but he would be redeemed if he had the balls to do one bold move.
In depression-era New York the shanty town's mayor is black, and he states that people there don't fight over what little they've got, and Shakespeare asks Martha what country she's from that she gets away with dressing how she does. Now amplify this for every historical episode for multiple seasons if the Doctor was black.
B) No, it isn't. The format would be changed too much because as someone else stated earlier, a woman or a black person back in the 1500's simply wouldn't be listened to, and this show is built around the idea of adventures in time and space, not tackling race or gender issues.
C) True, but historically the powers that be weren't, and it is not the Doctor's role to be the projection of a diverse and multi-cultural audience's view of the universe. That job is the companion's, the Doctor is largely there to bring them to these places and sort out the dangers there.
And as someone else said earlier, filling a quota on 'diversity' is a meaningless gesture, as it changes nothing about the show except bragging rights that said show is diverse, which in itself proves nothing other than the showrunners aren't completely closed to the idea of having a non-white male as lead.
D) Redeemed in the eyes of who exactly? Certainly not in my eyes since it'd largely be an empty gesture, and definitely not in the eyes of the large portion of the fanbase that loathes his writing with the likes of River Song of late.
RTD in many respects was better than Moffat in terms of being diverse. He had numerous strong females, he had black characters and he had gay characters.
These characters were women, black and/or gay but these traits didn't DEFINE them, but everyone was at least acknowledged it as a fact.
Moffat's idea of being diverse so far has been for minor characters with little to no characterisation to just randomly drop the fact that they're gay, usually to nothing but a raised eyebrow from somebody, which to me is not progress, and I doubt would magically change if the lead character was suddenly black or female, in fact I think those moments would become MORE numerous and in fact be amplified.
Keep in mind I am not against a black or female Doctor anytime soon. I am however against it just because there's some fictional quota that needs to be met in terms of equality.
If this is to happen, it needs to be done right.