The purpose of the parable was to encourage
the healed blind man. He saw that it didn't
matter that the Jews had cast him out of the
synagogue.

Jesus was the door of the sheep. "By me if
any man enter in, shall be saved, and shall
go in and out, and find pasture." John 10:9

It also showed that the rulers of the Jews were
hirelings who were in it for what they could get
by fleecing the sheep.