So in Prometheus when Shaw says: "They changed their minds, I want to know why.", I've thought of something up and just decided to share it with you guys. In Alien, the Nostromo was returned from the planet Thedus to Earth. And the Weyland-Yutani corporation heavily mined the planet Thedus for their natural resources; as it says here:
Thedus is a planet outside the Outer Veil regions rich with natural resources. The Weyland-Yutani corporation mined Thedus extensively throughout the twenty-second century and it was on its return from Thedus that the Weyland-Yutani commercial hauler USCSS Nostromo discovered The Derelict on Acheron LV-426. The UAS Archangel crashed on Thedus in 2109. Maybe Thedus could have been the Space Jockey homeworld, and they were pissed that the humans were destroying their natural resources, so they decided to destroy the human's resources to get back at them.
Thedus is a planet outside the Outer Veil regions rich with natural resources. The Weyland-Yutani corporation mined Thedus extensively throughout the twenty-second century and it was on its return from Thedus that the Weyland-Yutani commercial hauler USCSS Nostromo discovered The Derelict on Acheron LV-426. The UAS Archangel crashed on Thedus in 2109. Maybe Thedus could have been the Space Jockey homeworld, and they were pissed that the humans were destroying their natural resources, so they decided to destroy the human's resources to get back at them.