If it "feels good" to the angry parent, then that angry parent shouldn't be a parent - plain and simple as that. With three kids, I can count the number of times the whole brood got it on the fingers of one hand - and three of them were my son. They were done with the cry and on about their business long before I stopped feeling bad about it.
corporal punishment is just one tool in a parents bag. If some parnts choose not to avail themselves of that tool, fine. Just like some parents don't believe in grounding a child. As long as the child grows up to be a well adjusted, contributing Adult, the Parents have done their job.
One more comment, concerning the screaming child in the supermarket. At onetime, the general concensus among child "experts" was to ignore the child that was aving a "fit". To "acknkowledge" the childs behaviour in any way would just reinforce that behaviour. Parents were old to ignore the child and eventually the child would learn, on his or her wn, that that type of behaviour would not garner the child what he/she wanted. Yet there are people on here, that have said some not so nice things about the parents that follow this teaching.
The point is, not ALL things work for ALL children, and the "experts" don't know it all. As a matter of fact, the "experts", through the years, have been proven wrong more many many times.