In your understanding Christ DID die for those that would not chose him. In your understanding Christ did die (in part) in vain.
You make God and Christ to be ineffective and inefficient. God and Christ are never ineffectual.
If just one of the persons that Christ die for is not saved, in the end, then Christ is a failure.
But Christ is not a failure and John 10:27 My sheep listen to my voice; I know them, and they follow me. I give them eternal life, and they shall never perish; no one can snatch them out of my hand.
Romans 8:38 For I am convinced that neither death nor life, neither angels nor demons, neither the present nor the future, nor any powers, neither height nor depth, nor anything else in all creation, will be able to separate us from the love of God that is in Christ Jesus our Lord.
So if an angel can not separate us from God, how in the world can you think that we can separate ourselves?
Christ died for us, his sheep, and there's nothing we can do to make his sacrifice ineffectual.
Peace