If reincarnation is false doctrine, why didn't Jesus rebuke the disciples for believing in it ?

The disciples did not believe in reincarnation. Jesus told them that the man was born blind so that He could heal him at the very moment they walked past him and asked their question. It showed the disciples that Jesus was indeed God. A newborn has not committed any sin. God says in Ezekiel 18:20 "The soul of the one who sins is the one who will die. The son will not share the guilt of the father, nor will the father share the guilt of the son". So his blindness could not have been attributed to his parents' sin.