It was right there in what you quoted from my post.
I ask again, why would a perfect God create humans that would "Fall".
OH! Well, that’s a different question.
If you’re truly interested in the answer,
and not simply trying to “gotcha” a Christian with a lame question like “can God create something He can’t move”,
there are several sources available that are much better than some anonymous guy on a political board.
I’ll take your question in good faith, regardless of how it was intended.
The topic you’re looking for is “free will”.
CS Lewis (Mere Christianity) explains it this way - those creations that are capable of great achievement are also capable of great evil. If we were automotons incapable of choosing wrong, we would have little capacity to achieve great things. Short answer, given in good faith. If you want more detail, go to Mere Christianity.
If you’re just looking for a fight, don’t bother.