exactly my thoughts

ya the jab at capitalism irritated me as well, I miss Doctor 4 and his reasoned Thatcher BBC era speeches that at times smacked of libertarianism

Indeed Moffat seems obsessed with a negative dystopian view not only of humanity but the entire universe. It's easier I suppose to elevate the Doctor to an avenging demigod (in Moffat's own self-aggrandized image?) Can't drama be written with a more optimistic view? Show alien worlds that have it together without some hidden grotesque flaw indicting the entire world? Just a bad apple thrown in for conflict?

1. The whole Zombie-genre was political and anti-authoritarian/anti-colonialist from the very beginning, but at the latest since Romero's Night of the Living Dead.

2. The message is not that the free market is bad, but that capitalism is dangerous. And we see this from the start of capitalism as an intention of this economic system: using the egoism of individuals for the benefit of the community. We can already read about this in Adam Smith's works and this is why capitalism is so successful and has made our world a better place with more wealth, less death and sickness. But I think we can all agree that capitalism has the potential to destroy us all if it isn't regulated. In the scenario in Oxygen it isn't regulated and thus profit is worth more than a human life. If you don't see this trend today in the way big companies treat workers in third world nations, then you surely must inhabit a different reality than me.

I miss Doctor 4 and his reasoned Thatcher BBC era speeches that at times smacked of libertarianism

Libertarianism is the opposite of authoritarianism. Alternatives to capitalism are communism or feudalism. Capitalism does not equal libertarianism. One is about an economical system and the distribution of wealth, the other is a political philosophy about liberty. Though historically many capitalist systems have also been libertarian, this is not a necessity.

Can't drama be written with a more optimistic view?

Yes, but drama always needs conflict. I would presume that most DW stories set in the future and/or space are about dystopias. For the RTD era:

• Dystopias: The Long Game, Bad Wolf/The Parting of the Ways, New Earth, Gridlock, Utopia, Voyage of the Damned (btw VERY similar to Oxygen), Planet of the Ood, The Doctor's Daughter.
• Utopias: Maybe The Waters of Mars?
• Neutral ("Bad-apple") future scenarios: The End of the World, The Impossible Planet/The Satan Pit, 42, Midnight.

For the First Doctor era (I've only seen the serials which are still complete):

• Dystopias: The Daleks, The Keys of Marinus, The Dalek Invasion of Earth, The Space Museum, The War Machines, The Tenth Planet.
• Utopias: None.
• Neutral: The Sensorites, The Rescue, The Ark.

Sooo, I don't see that much difference to Moffat today. Do you? Really?

• Dystopias: The Beast Below, A Christmas Carol, The Rebel Flesh/The Almost People, Asylum of the Daleks (???), A Town Called Mercy, Into the Dalek (??), Time Heist, Oxygen.
• Utopias: I'd argue for Kill the Moon.
• Neutral: The Time of Angels/Flesh and Stone, The Girl Who Waited, Dinosaurs on a Spaceship (???), The Rings of Akhaten, Nightmare in Silver, Mummy on the Orient Express, Under the Lake/Before the Flood, Smile.

But I think we can all agree that capitalism has the potential to destroy us all if it isn't regulated. In the scenario in Oxygen it isn't regulated and thus profit is worth more than a human life. If you don't see this trend today in the way big companies treat workers in third world nations, then you surely must inhabit a different reality than me.

Yes there is potential. China blends communism with capitalism. The worst air pollution in the world resides in China. And I wouldn't be surprised if lives have been shortened as a result. Capitalism needs regulation. However "Oxygen" generalized it as an absolute paradigm.

What I meant in my original post re: utopianism is the overall theme of Doctor Who placing the Doctor as the figurehead of what utopia should be. Hitler had his idea of utopia. So did Stalin. So did the Borg. The Daleks. My point is hell is paved with utopian intentions and I wish DW delved more into context and devil's advocacy instead of simplistic preachy absolutes.