Like every plot twist in Doctor Who, it seems the cast and crew knew the departure of Matt Smith was coming far in advance of when we did.
The show runner told Entertainment Weekly recently that though he tried his best, he couldn’t get Smith to stay longer than the first-post 50th anniversary Christmas special, as planned when the actor took on the role:
We discussed ages ago that we would do three series and then he would do the 50th and then he’d do Christmas. That was Plan A for a very, very long while. That may sound cold that it was so far in advance but you’ve got to plan a career. [Laughs] The question was, “Will I be able to talk him out of it?” We went out for lunch and he said that he’d come very close to doing another series but it was the same argument: “If I do another series, I think I might do two more series, or three more series. I think I might never leave.” It’s that thing of wanting to leave while you’re a huge hit and not let it tail off. It’s part of the ecology of the program, it’s part of the DNA of the program, that there is going to be a new Doctor now and then.
Given the structure of the show, I don’t think anyone can begrudge a Doctor actor the change to go on and do something else with their career, especially given the show’s modern penchant for hiring relatively unknown but most of all young actors, ones at the beginning of their careers rather than the end or the middle. And the work schedule of such a role doesn’t leave a lot of room for other professional pursuits. Not that Moffat and team didn’t try to create some room if it mean they could convince Smith to stick around a bit longer:
It’s also, it has to be said, an overwhelming schedule for the actor playing the Doctor. As a workload it precludes you doing anything else. It precludes theatre, it precludes any significant other television or film work really. And even trying to crowbar some time in for him to do other things — which was part of our charm offensive — in the end he wanted to go and develop the other parts of his career.
The search for a new Doctor is always an exciting time to be a Doctor Who fan, and while I don’t think we’ll see a female doctor this time around (nor do I particularly want one at this particular juncture in the show’s history), it’s been really interesting to see the number of folks out there, fans and famous, who think the TARDIS is big enough on the inside for some genderswapping. We’ll just have to wait until this fall when filming begins on the Christmas special, when the BBC will have to announce their pick for the next Doctor.