i was joking about the first comment. kinda. it has nothing to do with your being a responsible, tax paying citizen and everything to do with your limited view on a subject that requires broader thought. but it was a joke nonetheless.
anyways, it makes plenty of sense. you're thinking about aliens as if they're human. aliens probably behave in ways and have motives that we cannot comprehend. for some reason you assume that they want to come here to destroy us. why? it's more likely that they would simply be benevolent observers who look at our destructive nature and know that we're not ready for the truth.
i dont really believe that this pyramid was built by aliens. its an interesting thought though. findings like these just prove that the ancient world was far more advanced and interconnected than we give them credit for. until we really understand how the early civilizations were doing these things the door will always open to speculation like this.