Questioning about whether the actress cast is likely to be a good fit? Fine. Worried about the writers will forget that they're writing the Doctor just because she's female? Fair enough. Appalled that the producers had the temerity to cast a woman to play a member of an alien species which has previously been established to switch identities, including gender, throughout their multiple lives? Yeah, sure come up with all sorts of reasons but it comes down to not wanting a character to come down with girl cooties. Which is all sorts of amusingly sad.