I watched Doctor Who through the Ecclestone and Tennant years and for maybe the first series with Matt Smith, who I think is a good actor but I just didn't like him as Doctor Who, though this might also be because the writing went downhill at the same time, or maybe the writing was always the same and I just saw through it more when I reached that age.
Having Doctor Who as a woman is a strange one, there's nothing inherently wrong with having a female in such a big role and although I'm not massively clued up on the "lore" or "rules" about the Doctors regeneration, I don't believe there's anything wrong with him becoming a woman in that regard.
The problem is that there are some characters, James Bond and Sherlock Holmes moreso than The Doctor, which are male. Some people (not many) are very vocal about how it's sexist to insist that these characters have to be male, and how it represents some great victory for equality to have a female Doctor, but where their logic falls over is when you start putting the boot on the other foot.
If the next remake of Mary Poppins or Wizard of Oz had a male lead character as Mary or Dorothy, would people celebrate the victory for equality? No, they wouldn't, which goes to show it is not equality that's being celebrated, the celebration is for internet pitchfork mobs scoring a victory while convincing themselves that they're fighting for some great just cause.
The female Doctor doesn't bother me. The actress I've only seen in Black Mirror but she was good, and good luck to her. What bothers me is the reaction of the melts on twitter who somehow manage to convince themselves that this is evidence of some brave new world where equality rules, rather than seeing the truth before their eyes that it's another case of media bending to pressure from a minority of vocal idiots in the knowledge that this meaningless decision will be celebrated as a ground breaking leap into the future.