You're not answering the question. Why did God choose to create people who would reject Him, knowing they would go to hell? He could have chosen not to create them. Why didn't He?
God created them all the same. There was not any created for hell. According to Calvinist God recreated some after the creation. He regenerated their heart so they were a different creature than what he first created, when He created all alike.
Man fell of His own choice. God created man subject to vanity but man didn't have to sin, he chose to sin and hence the fall. Jesus died for all but man had to choose Him and "believe" in Him to be saved. According to Calvinist you take away this ability of man to choose and give him a new creation with a different heart a "regenerate" heart that would believe in God and be saved. We say that after the fall that is why Jesus stood as a slain Lamb from the foundation of the world so all men could choose and believe and then their hearts were changed from a heart of stone to a heart of flesh, therefore it was man who chose good or evil and not God who recreated some so they chose good.
Calvinist believe in a "recreation" of some men so they would choose good, and they call it "regenerate".
It is not that this "elect" would believe in God and therefore be saved. It was according to Calvinist, a change made in the creation itself. The heart that man was created with was completely changed to a different heart and would no longer be like the creation but with a "regenerate heart" that couldn't do anything else but believe in God.