Cameron removes the human to spore stage

leading from

Aliens

a) Jim Cameron's way
James Cameron decided to do away with the human to spore part of the alien life cycle that had been left out of the original version of Alien. Ridley's actual idea was that the humans taken away by the alien and cocooned, were actually food being devoured by the alien's young as would Dan O'Bannon's idea have been,

b) Jim Cameron's misunderstanding I
He did not understand the concept, why it was that he didn't find out the truth can only be guessed. He was coming up with an argument not based on facts about what the actual concept in Alien was, but based on his own misunderstanding about the idea. He decided that the human's bodily cells were actually metamorphosing into spores rather than being eaten as food by the spore material and this wasn't actually part of the original concept

c) Jim Cameron's misunderstanding II
If he had based his argument on why he didn't want to use the "human to spore" stage of the alien's life cycle on the facts behind the original concept, he would not have been able to denounce it as illogical as it was just inspired by spiders cocooning their prey and various insect young eating their hosts that they've been implanted into while they developed.

d) My other thoughts
I'm also looking at the possibility that what we see of the cocooning process in the Alien director's cut compares to the growth of fungi

e) See also Creation of the Spores

Source quotes

1. Starburst: Haven't you messed around with the alien life-cycle in Aliens?
   
   James Cameron: Only in respect of Dan O'Bannon's original concept. It doesn't violate anything that audiences saw within the final act of Aliens as the cocoon scene was removed. If you follow Dan's original concept, the closure of the original cycle was the human host turning back into a cocoon. I never found that to be very satisfying as it showed, when one had the facehugger attached, the embryo implanted, and when it burst out it killed that person. There was nothing going on with John Hurt in that respect. So there was a different version of it when the alien grabbed Harry Dean Stanton and presumably put him into a cocoon. It's certainly no great logical detour to assume that it might have used him as another host but I think it would be a bit odd that he turned into an egg. That's something that would have been hard for the audience to swallow because it involved the transformation of the human host and although one can assume the alien can metamorphose,  to have its biological properties take up residence in a human being and change it was going beyond the ground rules they set themselves. One of Alien's great attributes was that it set up a very weird biological process but it has a basis in science fact all the way through like the cycle of a digger wasp which paralyses its prey and injects an egg into the living body to mature. There's a validity in all of that but I dispensed with it because we never saw that in the film anyway. Had it appeared in the film I wouldn't have violated any logic turbulence. (Starburst 98, October 1996, interview with James Cameron by Alan Jones)
2. James Cameron: I think it's strange to think about further victims becoming hosts. It would be somewhat difficult for audiences to swallow because it requires the transformation  of the human host. You can accept the fact the alien transforms but to have its biological properties take up residence in a human being was a direct violation of logic. You can't suspend belief that way; it's too absurd. (Skeleton Crew, August 1990, p22))