I’m new, never played it, but had quite extensive information about game from friend who made me join.
I think I would be that player, so maybe I can say from his perspective. Or, maybe it’s not his perspective, but still one that would apply in this situation.
So I got you as an ally. You helped me, I helped you. Without mutual cooperation, we wouldn’t get that far. We are so close from winning… So I made us win. And you are better than me, so you deserve first place.
And I feel like winner too. Our alliance won. And it’s ok.
Also with this, I secure second place (?). And second place is better than third (according to points you get, what I understand from rules).
And I don’t like putting a knife in your back. I would fight to the last ship to win, with my enemy, I would do everything to get first place. But you are not my enemy. What you call “anti-climatic end of game” I call climatic win of fellowship and heroism. What you call climatic knife in the back, I call tainted victory filled with regret and sorrow. I have galaxy… But it’s full of dead bodies of your people, my once best friend. Was it worth it?
For some: yes. For other: no.
Of course my perspective can change AFTER playing some games