system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The ending to the ghost in the shell movie

I'm having trouble understanding project 2051's motives. 2051 wants to combine with kusanagi to make an optimized machine.

2051 says that he picked her because they are a lot alike. He can't simply make a copy of himself, but what separates the two besides the extent of 2051's knowledge? I feel like this plays a huge part in what the movie is trying to say.
gpt
2051 stated that copies do not evolve, it be like cloning a human with a heart defect. All the clones will have the same 'error' as the original and once that 'error' becomes challenged by an external factor, the whole system collapses (the race becomes extinct if you will).

By merging with the major, 2051 ceases to be as does the major and they become a new, third entity. Kind of like how a man and a woman makes a child - oh you have your father's humor, but your mother's eyes. 

> but what separates the two besides the extent of 2051's knowledge?

The Major is so much machine that basically the only thing left of her human self is her brain and spine. She questions her humanity and keeps looking for some definitive proof that she's alive. 2051 is in a similar situation and as the Major browsed the net in search of her answers, 2051 picked up on it and decided she was worthy to be its partner. 

By merging they'd get their answer - they were alive, even if they weren't before.