I enjoyed the film. I'm personally surprised at the negative and angry reaction directed toward David's involvement in the creation of the xenomorph.
In my own opinion, this explanation is far and away more interesting than the xenomorph as a biological weapon of the Engineers.
I actually think that viewing the alien as a tool for another species is quite demeaning to a creature described as the "perfect organism". The fact that the xenomorph is the product of Engineer technology and AI ingenuity is far more interesting and satisfying as it explains the physical power of the organism and also adds to the fascination of Ash and other AIs in the series. AI, like the xenomorph itself, also lacks morality - another connection that makes sense.
I think many fans become convinced of long-held theories, when that doesn't turn out to be the case... they get disappointed. But, if you think of it, the xenomorph as some sort of subservient slave species to a Space Jockey/Engineer is very demeaning. It either turns the alien into a tool or makes them weak.