I agree, you have to look at what the shop actually sees everyday. THis isn't quite the same thing, but it made me think of a few things from my days as a mechanic. A lot of new car mechanics probably wouldn't know how to or want to deal with timing points ignition or rejetting carbs or adjusting mechanical fuel injection systems and why should they? The old cars are usually toys maintained by the owners who know that tech from back in their day or are brought to specialists and the few left out of that category that a regular mechanic might see roll into the shop would more than likely be toilet cars where everything they touch is near end-of-life and ends up costing them a fortune in lost time fixing things they broke while trying to cure the original problem for a customer that likely has no money and will balk about even the original agreed upon price. I used to work on cars and boats. The car shop owner was a great mechanic who took everything and everybody and charged too little because most of his customers were poor and he felt bad ($60/hr and he let people bring their own parts vs. even Pep Boys charging $90/hr. and upcharging parts per normal, though why someone would bother with Pep Boys when a dealer wouldn't charge much more, I don't know and is too far off topic.) and between not charging enough and mostly boxing himself into a corner with customers whose cars were on their last legs and their wallets on their last dollars, he ended up broke and in a nursing home with a broken body before he was 60. At the marina, we refused the toilet boats unless we were really desperate for work and they always ended up costing us money (but at least it put billable hours on the clock).
Obviously, old bike tech vs. new isn't exactly analogous to my examples, but I thought I'd throw it there for a little perspective from the eyes on the other side. I'm not saying there aren't bad mechanics or rip-off artists, but they need to concentrate on their bread and butter for their bottom line like anyone else. (Though, in my experience from both sides, I find rip-off artists are a lot rarer than popular opinion—at least among independent mechanics—as reputation makes or breaks someone. Most often overcharges and failures are bad mechanics using the customer's wallet to diagnose problems a good mechanic could probably get first or second try and a defensive attitude from insecurity when challenged. Like many other mechanical professions, this is and will only get worse as several generations of kids were taught that manual labor jobs are for the dummies and losers and, as a consequence, that's much of who went into those professions. Where I am, trying to find a good plumber is nearly impossible and they can charge whatever they want. Even the bad ones can basically work as they please as the total pool of plumbers of any ability is too small for the area. Of course, the real "dummies" got a degree in office dronery and most of them ride cubicles, unsatisfied and in debt, for too many hours for slightly above average living area salary or even well under, but I put dummies in quotes because we're all just victims of the system, one way or another ... Wait, what were we talking about? Sorry, I need to take my meds.)