I don't see what the issue is, or why people would think this is shoehorned in. I like Peter Capaldi and most of the previous doctors enough, but after over a decade of the modern Dr Who a lot of episodes are starting to get repetitive and dull. Recasting the Master was the best part of the last two seasons for me. The Doctor's been a collection of English white dudes from young to old time for something a bit different.

I recall talking to a female Dr Who fan about the time Matt Smith was cast, and the subject of the Doctor ever being a Woman or black came up, she didn't think it was possible that a woman would ever play the Doctor, but there you go.

Personally I wanted Richard Ayoade to be Dr Who.