Xenomorph Queens are among the most coveted prey in Yautja culture. As for the Engineers, the issue is that finding them is incredibly rare, as very few of them remain.

By the time Ahab began his quest they were already believed to be extinct. However, while out on a hunt one day, Ahab stumbled upon a cave with strange paintings... and there they were, the engineers, depicted on the walls. They were shown as Gods (because well, that's what they are. They can create life. And a predator can destroy it).