Yeah, most of use want everything at once but for it to last, it's spoon fulls of information we will get. Who knows the origins of everything? What I took the stance of, in order to quell my gamer rage, is "They probably just want us to start off as being just one of the soldiers but stumble upon the vex that sends us out to what we think is the root of our issues. Please remember when we beat the game, we didn't get any credits or anything like that. We got a cutscenes that caused us to think we gained some sort of triumph. But, she said it's only the Beginning which means we did nothing but fight someone whom was placed as a decoy enemy. We are just soldiers in a massive army.