I can see your point if you are talking about professionals receiving parts, but do you really want "Joe Diver", who dives 10 to 15 times a year working on his own reg? Take away the liability of the manufacturer, do you really want the liability to fall on you or your dive shop?
I believe it is good business practice to keep service kits out of the hands of the average diver. There would be a rise in dive accidents, and perhaps even a move by the government to regulate our sport. I know this is looking at the dark side, but it could happen.
As far as the original question, I would chose the Scubapro. I've been diving it for years and have had no problems. You also get a great warranty program, with free parts for life.