Is shunning an act of kindness so that "sinners" will experience the profound loss of God's favor and want to repent and rejoin the flock?
I must admit that I used to think it was.
If after a sufficient time the "sinner" does not return to the flock, then "kindness" begins to be seen as it honestly is: punishment, sometimes for the rest of your life. If there is "repentance," perhaps it is forced so that the person does not lose all those whom he loves.
Then it negates the scripture, "Love never fails."
The profound loss is theirs.