"Rudimentary creatures of blood and flesh. You touch my mind, fumbling in ignorance. You are incapable of understanding." "Reapers? A label given by the Protheans to give voice to their destruction. In the end, what they chose to call us is irrelevant, we simply....are." "Organic life is nothing but a genetic mutation, an accident. Your lives are measured in years and decades, you wither and die. We are eternal, the pinnacle of evolution and existence. Before us, you are nothing, your extinction is inevitable. We are the end of everything." "The cycle has repeated itself more times than you can fathom; Organic civilizations rise, evolve, advance, and at the apex of their glory, they are extinguished." "You exist, because we allow it, and you will end, because we demand it." "Your words are as empty as your future, I am the vanguard of your destruction, this exchange is over."

extinct super-advanced alien race leaves technology around for humans to use

Blame Erich von Däniken for writing "Chariots of the Gods?" and inspiring a generation of science-fiction authors.

He started it hey? I'm kind of annoyed at the lack of space games that don't assume aliens exist and are out to get us, they all end up being very similar.

Well, his book claims the Egyptian Pyramids, Stonehenge, Nazca lines of Peru and Moai statues of Easter Island were all the work of aliens (or humans using alien technology). This inspired stuff like the original Battlestar Galactica TV series and the movie Stargate.

As if you wouldn't play as a female Shepard. Who wants to see some dude bone an alien?