Moffat has gone on record before as saying he's not opposed to a female Doctor (something people often seem to forget), but even when he first fielded the question to a live audience, the reception was rather frosty.
After Matt was announced to be leaving, of course plenty of female Doctor rumours started spreading. And I have to be honest, just like Moffat himself witnessed, plenty of the people I saw being against a female Doctor were women themselves. All for a large variety of reasons, of course - though a disturbingly large amount came down to not having a Doctor to find 'hot' anymore.
For every fan praising the idea, there were at least five rather petulant ones claiming they'd stop watching the show if it ever happened. Ironically, the general audience seemed far more receptive to the idea than the hardcore fanbase.
It's so easy for us to get swept up in our talks of equality and representation that we sometimes forget this is a TV show that needs good ratings, otherwise it'll never last long enough for us to ever get a female Doctor. While it seems ridiculous to us that people can be so against the idea, we have to remember that a lot of people are.
Does that make them right? No. Does that make their threats of abandoning the show worth paying attention to? Sadly, yes.
I'm sure we'll have a female Doctor in the future - god knows I want it like burning - but given how much of a powderkeg this issue became in the run up to Peter Capaldi's casting (anyone remember the disgusting comments aimed at Helen Mirren a few weeks back?), I'm gonna have to agree with Moffat on this one - with so many people threatening to jump ship over the issue, this fandom just isn't ready for it yet. unquote
two. At least with this method shut the the whiners since tecnically the doctor was an old man.