Fifth Doctor actor Peter Davison was asked this question this week in an interview with ABC News Australia. Davison said:
"I speak now as a fan who grew up watching it: I have trouble with the idea of a female Doctor, only because I reckon if you're born on Gallifrey a man, you're probably a male Time Lord."Davison expressed that this was his personal opinion, but went on to explain why he thinks it wouldn't work. He said that the strong female companion and troubled Doctor combination has been integral to the success of the new series.
"It seems to me if you reverse that, if you have an uncertain, fallible female Doctor with a really strong male companion, you've got more of a stereotype than anything else."Peter Davison played the Doctor from 1981-1984. He is currently in Australia to narrate the Doctor Who Symphonic Spectacular, which played in Adelaide on 24 January, and will tour Perth, Sydney, and Auckland, over the next two weeks.
[Source: ABC News Australia]