I truly believe in personal freedoms. If a person chooses to shun someone for their own reasons, I would not say that it is outright wrong. I might feel that way, but I wouldn't decide for someone else. And I think the problem with JW shunning is that "someone else" makes that decision. Watchtower makes blanket rules that apply to your teen who research Jehovah's Witnesses but was baptized as a preteen and the rules apply equally as well to a former member that raped your daughter.
As for me, if my own family member was an unrepentant murderer, I might still visit him in prison and make sure he gets the proper legal counsel and mental healthcare he needs. That doesn't mean I approve of what he did or thinks.
Is shunning 100% wrong? For me it is. It is 100% wrong for an organization to insist upon it.