Tangential to Alien Earth, but here's a theory:
As far as can be seen from Alien-Alien3, Weyland Yutani isn't an all-powerful megacorp; and they aren't obsessed with the alien. Much more likely, the alien is a side-project to them that's on a strict budget.
Look at Alien: The Company knew where to look. But they don't send in a specialised team; they re-route a freighter that's on its way, anyway, and task an android with the retrieval of the lifeform. This sounds a lot more like the gamble of one executive who wants to make it big, pushing something the board is not necessarily convinced of, than a megacorp mobilizing all their ressources.
Then, the whole thing obviously gets forgotten about. Which makes sense: It was a failure, whoever was pushing for it took the fall, and the people who sent colonists there didn't know about this side-project.
Then they find Ripley adrift, and the whole thing starts again: They dig out the old files, realizing that "Oh, yeah, there was this alien project that didn't work out." Burke pushes for it, he wants to make it big. Then the comms black-out. The Marines are sent in ... but by whom, exactly? WY doesn't own them, obviously, because if it did, they would have clear orders to bring back a specimen. No, as far as they are concerned, they're there for a bug-hunt/search and rescue. The company sends Burke along, who is hardly that impressive an operative. So everything points to this being HIS gamble, with WY saing: "Sure, give it a try. But we're not throwing buckets of money at it."
It all points to ambitious lower-tier executives taking a gamble. And to a company that actually turns every penny, trying to get a lot of things done on the cheap.
Now, Alien Earth obviously doesn't share this interpretation, but I'd still be delighted if, should it come to this, the "Nostromo project" would just be a project among many, and not what's WY is suddenly all about.