I also just find it kind of ridiculous that after all that the Engineers are still kicking - and apparently just hanging out on their homeworld a mere 20+ years before Alien, despite their major cataclysm - all so David can end his and Shaw's cosmic journey by abruptly killing them, presumably so Ridley Scott and Fox can say 'all that space jockey stuff is gone, relax everybody, we're straight back to the aliens!'
And even if you don't want to go back to that stuff from the last movie, fine - but how and why are the legendary space jockeys, supposedly long dead, all still hanging out alive in what is nearly contemporary times for Alien? At best, if there were somehow survivors they should be beyond the reaches of where humanity (i.e. Covenant, not David and Shaw's juggernaut) can travel. It just destroys any mystique, all so they can insert a contrivance of 'look, David shows up and kills them all, we're done with that.'