Diana would not have felt comfortable ever agreeing with someone’s decision to abdicate their throne. It was not about duty or responsibility, but simply that for her to agree that someone was unfit to rule would have been horribly unkind, and except in the case of a madman or a murderer, Diana tried to be kind in every situation. And it was not for her to judge what might be best for another’s kingdom. Thor knew himself better than she ever would, and part of being a good friend was accepting his judgement of a situation that was none of her business.
She did, however, have some thoughts on this entire situation. At first, she was a bit stupefied, because what actual idiot took six people against an entire planet of other people that already hated them? And then it occurred to Diana that her own idiot self had traipsed away from Themyscira to go slay a literal God with, drum roll please, one very confused human. Do you know what, maybe this was why neither of them were actually on a throne, and that amused her so much that she had to fight to keep her giggles in. Was she or was she not an adult, O Lord Zeus?
“I do not think you would make such a mistake now,” she said, once her amusement had passed enough that she could. “But that is part of learning, you know. Making mistakes is how we get there, and it does not seem to matter if that is God, Amazon, or human.”