The only proper reason to give an invitation is that God calls people to decision.
Not a few of us have been turned off by public invitations that offended our theology, our integrity, our sensitivities.
Some "altar calls" I wish I hadn't heard, and I doubt they altered anyone. I recall a healing evangelist during my younger days who cajoled and threatened his audience until the number of people God had "revealed" to him came forward that night. But I also recall another man with the gift of healing who laid his hands gently but with authority on those who came to kneel at the altar of an Anglican church.
I remember an evangelist in the Wheaton College chapel whose finger swept the audience like an avenging angel; his invitation was so broad we felt we should come forward if we hadn't written our grandmother in the last week! He squeezed and pleaded as if Jesus were some kind of spiritual beggar rather than the royal Lord. But I have seen Billy Graham stand silently, arms folded, ...1