Ridley Scott confirms David WAS the originator of the xenomorph AND that the beings he bombarded were in fact engineers.

As a major Alien fan since 1979, I respect all views here, and I too, was at first "let down" by AC's storyline.  The whole "David created the xenomorph as we know it in Alien" first let me down, but the more I think about it, it makes sense. I've seen AC more times than I would like to admit, but I love it.  On just a movie level, for me, it's a combination of everything great from the Original Alien and Aliens.  For us hardcore fans, I totally understand the frustration of Prometheus and AC. I also respect the fact that the scare factor of these films will never reach the levels of the original Alien.  

If, like me, you go into Prometheus and AC as more of an informational exercise, to give answers, they get a little easier to swallow.

i will admit, I don't like the rushed feeling of Alien Covenant, the easy way out of having Shaw already dead at the beginning (a la Meichael Beihn in Alien3), and, sadly, Prometheus almost promised that we would see the engineers homelands.  I was looking forward to seeing an entire world looking like Giger created it, with all sorts of acid for blood creatures flying and crawling around.

So, now we know that David despises humans for being so conceited to create him, he wants us all dead. I'm okay with this and will accept it as Canon, but I still have issues with AC's treatment of how Shaw and David entered this planet. In one moment, they want us to believe that the jauggernaut crashed and destroyed tree tops, then, they show the ship "docking, then unleashing the pathogen on the engineers.

My hope, as a fan, is that they hit small backstory showing the original origin of a derelict ship with a Grand-daddy of the Engineers flying with a payload of eggs/possible queen, crashing on LV-426.  For the life of me, I can't imagine any other way... it's not like David can go up to an Engineer and say, "Hey I made this stuff and I need it Hot shotted across the universe."  The engineers would rip his head off again!

Parasite68

"My hope, as a fan, is that they hit small backstory showing the original origin of a derelict ship with a Grand-daddy of the Engineers flying with a payload of eggs/possible queen, crashing on LV-426.  For the life of me, I can't imagine any other way... it's not like David can go up to an Engineer and say, "Hey I made this stuff and I need it Hot shotted across the universe."  The engineers would rip his head off again!"

My best guess is that at some point, the engineers are going to find out what David did to their homeworld and that he has been abusing their technology. A ship will likely come, kill him, and capture his cargo (either to transport it to a containment facility or to dispose of it). This would be a pretty easy set up for the space jockey impregnation and crashing on LV-426

Scott has changed his tune on various aspects of the franchise many times before and likely will again.

@monsterzero yes the xenos on their own are hard to make a story out of but it could easily be done.  But lets say you want something more intelligent to be the baddie well that's what the queen was... and telepathic communication. What if we have only seen the children even the queen being not so old in aliens. Maybe there can be an origin of the black goo a superbeing of sorts thousands of years old or more.  Ridley kept hinting at multiple levels of evolution and races out there.  Well the engineers stated off looking like very advanced beings until this movie.  Ann's looking at their technology i could easily imagine us reaching that level in the next 200 years or so faster if the right things happen and of course we don't destroy ourselves! So... we're is the 1000s of years advanced 10000 100000 millions billions? There could be such a vast gap between each race each level looking like a god to the lower ones...

That old theory of the black goo being a way of destroying a planets inhabitants and storing the DNA ready for something to come along and absorb all the rich bio diversity was one of the best... seeding or guiding life letting it diversify and then soaking up all the lovely dna ideas adding to the soup of the super  being improving the design or what ever you want...

The way I see it David recreated the xenomorphs, instead of creating them. The xenomorphs were already in existence, hence the mural. Why else would it be there? And what about the dead Engineers in Prometheus? Didn't they have open chests, like something burst out of them?

Now here is a theory I made up which encompasses all origin stories. 

Once upon a time the Engineers came across the Alien homeworld. They captured a few aliens and extracted DNA from them. The Engineers tempered with the DNA ultimately resulting in the black goo. The goo has got the alienness and the agressiveness of the xenomorphs, thereby creating other types of agresive creatures, and changing human beings. 

It may not be the same goo we saw at the beginning of Prometheus, when one of the Engineers dissolved. Or even the one used in Alien Covenant, as we didn't see any aliens emerging from the Engineers. 

To be honest introducing the black goo was a mistake, I feel. It can be used for all sorts of things and methods, whatever the story asks for, and it has got a high X-Files vibe. Anyway we have to live with that.

So my theory is that the Alien Homeworld is still out there somewhere (as to their hosts, who knows?), and I also think we haven't seen the real Engineers' homeworld yet. Or planets they colonized. 

Someday I hope we get to see a movie told from the Engineers' perspective. We need some answers. There must be a good Sci-Fi and horror movie in there somewhere.