What I see is that the Time War has raged across time and space to such an extent that this unspeakable action of a double genocide is the only solution with the rest of the Universe on the receiving end of just such a trolley problem. That The Doctor of all people arrive to that conclusion is terrible. And his punishment for using the Moment is to live on knowing what he has caused in order to bring peace to the rest of the Universe.
And I think that is so prevalent in Doctors 9 - 11. The 9th Doctorâs emotional response to meeting a Dalek in series 1, and his elation when âEverybody Lives!â. The 10th Doctor living with the Survivorâs guilt until he snaps completely and goes Time Lord Victorious. And the 11th Doctor being torn apart about how he killed his own people.
And I donât think it says those things about grief at all, the Doctor is presented with hope at the end, and gives him a purpose again. He learns that he didnât commit a genocide on his own people, that he discovered that alternative solution to the trolley problem.
And the main purpose of fiction is at the end of the day to entertain, and what is a compelling narrative doesnât necessarily translate into real life situations.