Yeah, itÂ´s all about money.
Maybe you guys remember in the run-up to AVP with all that stuppid interviews P. Anderson gave. In one of them he mentioned the "boom-boah-great" huge explosion at the end of the movie and how many gallons of fuel they burned and how big it was and how many dollars they blew in the air by that god-damn s***. This was the time as my expectations for AVP got to the ground. An adolescent director speaking. Oh gosh.
So the budget for other fx stuff was limited. And thatÂ´s why a lot of cheap and untrained Czech helpers were working on the set.
My other opinion is, that fox fears the influence of Stan Winston. The old man isnÂ´t that suggestible like the guys from ADI.