They are like unto children sitting in the marketplace, and calling one to another, and saying, We have piped unto you, and ye have not danced; we have mourned to you, and ye have not wept.
Note 5 at Lu 7:32: This illustration that Jesus was using is speaking of Himself and John the Baptist. John came living a life totally separated from any of this world's pleasures. He ate locusts and wild honey (Mt 3:4), stayed alone in the wilderness, and preached a hard message of repentance. This would correspond to Jesus saying, "We have mourned to you." However, by and large, the people did not repent.
Jesus came eating and drinking and bringing the good news of God's mercy, but the people didn't receive Him either. God the Father used two different lifestyles to bring the same message of forgiveness in an attempt to reach everyone, but the people rejected Him.