I don't know what you lot watched, but that was the best episode in years.
Its exactly what Doctor Who can do better than any other sci-fi - wrap a morality story around a science-fiction skeleton.
It tells us that when it comes down to it, wars can be boiled down to one or two people having a choice to press a button or not; But at the end of the day most wars don't lead to total annihilation of the enemy or total victory, but instead to a place where those participants will have to sit down and talk and agree - except with many, many people dead before they sit down to talk.
And The Doctor isn't make a speech arguing for pacifism - how could he be a pacifist given his history? - but instead using the weight of his own history to plead, cajole, threaten the protagonists here against a pointless war.
Capaldi has never been better in the role - being ferocious, then quiet, intelligent then simplistic, using every part of his personality to manipulate both sides away from war. It's a masterclass and I don't think any previous Doctor could have pulled it off.
"This is a scale model of war. Every war ever fought right there in front of you, because it's always the same. When you fire that first shot, no matter how right you feel, you have no idea who's going to die. You don't know whose children are going to scream and burn. How many hearts will be broken? How many lives shattered? How much blood will be spilled until everyone does what they're always going to have to do from the beginning and sit down and talk."
All this is done in the guise of a Saturday evening family entertainment.
Frankly, if you didn't like it, then maybe Doctor Who isn't really your thing.