a) there is no doubt that some entirely "untrained" teachers are inspiring (I had some of them)
b) there is no doubt that overall we would prefer the people who teach our children to be trained. Among other things, training does weed out some of the hopeless, it provides a clear form of guided instruction in a difficult skill/craft, and it would be a fool who said that the kind of questions that training courses raise were not useful (what is the current research about HOW people learn languages.. etc).
The issue is: how far it is worth excluding some of the "naturally" good untrained teachers, for the benefit of ensuring a decent standard of all? On this I think I am probably with Hunt, but it is an arguable case.
More puzzling though was the whole issue of nuns and teaching, on which many people who have never met a nun seem suddenly to become experts.