Yessss! It's an interesting question, and the fact that the Doctor's politics are malleable (he commits a few genocides of his own) are because there have been so many writers on the show and they don't always get it right. The murders and genocides he commits tend to be very controversial amongst fans.

The core of the show's morality, excepting a few bad stories, is libertarianism and the defence of the rights of the individual against governments and corporations. We're talking about a male protagonist who is an eccentric, anarchistic rebel who defends the individual. That's incredibly rare in a genre which is dominated by military imperialism. Star Trek and Star Gate are essentially about the American military colonizing outer space. They might make excuses about being impartial, but it's a pretty shallow pretense.

I could talk about this forever, but there's one line that will always sum up Doctor Who's ethics for me. It's in an 80s story called Warrior's Gate, in which a suspicious-looking alien cat-person is being pursued by a lot of humans with guns. Romana, the Doctor's companion, goes to help the cat-person, and Adric asks her why they should take his side. Romana replies, "Because he's the one running away." It's such a simple reply, but it's also very powerful. You help the people who are being victimized — you can ask questions later.