I think that the reason it got outlawed was to protect those children that were very much being abused by adults who couldn't differentiate their emotions and frustrations from the actual act of discipline. And could hide being the rationale that it was their child and they would very much discipline them how they saw fit. This left very little room for government to step in for the benefit of the child. But this is very much a minority situation.
I think for the most part parents used an appropriate amount of "smacking". I for one was a really bold child, and to some extents a little shit, and I am glade I did get smacked from time to time. Because the way I was raised overall, inclusive of all discipline has culminated in me being a very socially aware individual.
You could argue that verbal and psychological abuse is far worse than a smack, so yeah I think this is a black and white (binary) approach by the government for something that isn't that simple.
In much the same way that our social welfare system gets abused by a small number of the population. But is ultimately a good thing. I think a more flexible approach should have been taken to what constitutes physical abuse.
But then the child welfare courts would probably be full of endless cases and appeals. So unfortunately we take a one size fits all approach.
Though I do believe you can still bring up a productive child without smacking. It just requires you to engage with them differently.
No harm in smacking from my view. But def not tantamount to children running amock if a parent cant smack them. Using that is just an excuse for weak parenting.
RE: SPANKING: Appropriate or Abuse