Feel free to interpret the ending as whatever you want, and that's your right, but it doesn't change my impression of the fact that it's so unbelievably boring.
Elaboration:
I think the
TVtropes page for this kind of story explains why I think the ending is daft very well:
"But the problem is, these things are actually being written by humans, for humans, and that usually means people want to see humans in an important, overarching role. To accomplish this, it is made clear that there is something special, something unique about the human character. It could be that humans are inherently noble, kind and idealistic, or that we never ever give up no matter how bad things get, or we are extremely curious and love adventure or simply that our very emotions are our strength. Whatever the case may be, humans are usually given some Western, humanistic value that somehow allows us to transcend our weaknesses and earn the admiration and/or fear of other, more advanced civilizations. Apparently everyone else is stuck in a rut, possibly as a result of being a Planet of Hats."
Neil deGrass Tyson explains it very well too in several videos:
Humans are too stupid:
http://www.youtube.com/watch?v=Tt0uV5d8tssHumans are designed badly:
http://www.youtube.com/watch?v=YCnGf37iiKU
TL;DR: The aliens' reasons for attacking us is too Hollywood. Humans are the best things amirite.----------
Since we're also on the subject, one of the best space game endings in my opinion is Master of Orion 2's ending. Where humans and a bunch of other races get together to transcend dimensions and defeat what they considered an intergalactic threat. However, they completely misunderstood the situation like an ant would misunderstand what the nature of the shoe that stomps on it does.
Instead of ending the threat, what they actually did was annoy the threat enough to actually notice them and they ended up getting obliterated and subjugated in such rapid fashion before being promptly forgotten again.
I think that's a more apt detailing of what it means to actually face up against an immeasurably superior force. The Half-life series did this too, which I think was really good.