As I intimated, I'm off this train. However, were I not, I'd say that definitions apart (and no definitions leads to chaos), licensing is something I have always advocated, not simply because it would, by testing, removed the worst charlatans, but in so doing it would offer the minimum protection to the public that it needs, no, should expect from the local city fathers.
In my own case, I lost nothing to shamateurs; they simply didn't/couldn't come near my client base - it was difficult enough for me to get there as a known, full-time pro - but I did go through the experience of my own wedding being shot by a doddery old bloke who had been the go-to guy in the minds of the good folks of the town and, consequently, of the in-laws-to-be who booked him. I think we bought a single print; camera-shake isn't pretty, and a pretty bride isn't improved by it.
The train is now in the distance, and as suggested, I'll pursue sweeter fruits than further train-spotting.
Rob, I worked for a wedding photo company, the one owned by Kodak in fact. To be allowed out on your own you first had to attend two training weekends and then accompany a senior photographer on three occasions and be marked on your work. If you didn't pass then you were out of it, doddery old men, and those who were not up to a good standard were not used, simple as. Kodak were not in the habit of employing shysters. Oh, and you had to own two MF cameras and be able shoot a wedding in about 120-150 shots of which 80 had to be good enough to show the bride. No dress rehearsals, no calling the models back for another go or asking them to hang around while you adjusted the lighting etc. It was a tough environment which is why a lot of pro's wouldn't do it.