I have come in peace with that aspect.
He's a grunt, a soldier, he's pissed that his ship got destroyed by a lower race he was supposed to destroy 2000 years ago.
I guess what he does is normal.
I'm just dissapointed that he doesnt get to fight (and the human survivor) what was unleashed in the base.
The massive engineer xenos that do very perverse things...
Man i would have loved that instead of just a baby one appearing at the very end for 1minute.