The Engineers either make us whole like David-the-Android and teach us everything.
OR
They wait eons of time for Mother Nature to do the seriously convoluted work and then give us a basic language lesson, and teach us nothing of any value.
WTF?
This story has no value. All it does is rape the movie ALIEN of some iconic imagery, shrink the Space Jockey to human size and retcon human history.
Bravo Ridley, bravo.