I saw the anti-soldier attitudes from The Doctor as a form of self-hatred. As in really hating the War Doctor, and in what Matt Smith became at the end of his life. So I had no issue with the attitude, except he had to be such a damn prig about that it just made him unlikeable. I'll grant that Danny was too childish in return, and especially so in the last episode because it didn't seem to be based on anything that had happened to that character. It was more like a meta-level indictment of the Doctor's character which could have come from another character with a long history, but instead we got Danny Pink. 
But as we know, doctors do go to war, right or wrong. Doctors must choose to kill a parasite to save a patient. To quote EPU, that's what it means to be a Chooser of the Slain. And this Doctor isn't showing his age, he's showing his childishness in not coming to terms with himself.
If it were me, after The Day of the Doctor, I would have made this season be about trying to find his way back to Gallifrey. The journey home is such an obvious plot, and a quest like that is still such a good uplifting story. It could take years to find it; I recall Odysseus having a hard time on a similar journey. But they wasted the best news for the Doctor and turned him into a childish grump, navel-gazing over whether he is a "good" man, and that was truly a waste.
-- ∇×V
But as we know, doctors do go to war, right or wrong. Doctors must choose to kill a parasite to save a patient. To quote EPU, that's what it means to be a Chooser of the Slain. And this Doctor isn't showing his age, he's showing his childishness in not coming to terms with himself.
If it were me, after The Day of the Doctor, I would have made this season be about trying to find his way back to Gallifrey. The journey home is such an obvious plot, and a quest like that is still such a good uplifting story. It could take years to find it; I recall Odysseus having a hard time on a similar journey. But they wasted the best news for the Doctor and turned him into a childish grump, navel-gazing over whether he is a "good" man, and that was truly a waste.
-- ∇×V