I've never had a problem with a well-deserved spanking, in the right place, at the right time and never out of a anger. I was only spanked or hit a very few times as a child but I remember them well and they were well deserved.
The problem with a lot of people, both JWs and non-JWs, is that they use hitting, spanking, whatever, as a substitute for real disclipline. They do it in anger, or on the spur of the moment.
To hit a child at the KH or church is not really discipline, but a parent acting out in embarassement or anger. Real disclipline will come later, at home. I dreaded getting into trouble at the hall, because I knew there was going to be hell to pay when I got home. The dreadful ride home was as much punishment as the punishment itself.
I remember people hauling kids to the bathrooms for whippings and we all kind of nodded our heads knowingly, but really, is all that drama necessary?
The best disipline I saw was an elder whose pre-teen son was misbehaving. He made his son get up and walk out to the lobby, staying 3 steps in front of his dad all the way. The son would stop, look back, Dad would stop, motion for him to continue and they had a deep man to boy talk, no violence, in the lobby. They came back in side by side, Dad's arm around the son and they sat down and the son behaved the rest of the meeting.
The worst I saw was an elder with his 3-4 year old granddaughter. The granddaughter whose parents were irregular was brought to the hall by the grandparents. This child was not used to sitting still for two hours. The elder grand-dad had his fill of her fiddling around, jerked, and I mean jerked, her up by the elbow, it had to hurt, I saw the pain on her face, and dragged, and I mean literally dragged her to the parking lot where he beat her, and yes, I mean beat her. I was on attendent duty, I saw the whole thing. It was abuse, pure and simple. I was upset at his behavior but didn't do or say anything. Today, I'm ashamed that I at least didn't voice my disapproval at him for his conduct, let alone letting her parents know later what happened or complain to the other elders.
My long-winded point is that being a JW doesn't mean you're going to be a good parent anymore than it means that you're going to be a bad parent. God's holy spirit(tm) is not on these people anymore than it is on anyone else, so therefore, you're going to have a wide range of good and bad parents and children.