I would say the manufacturers might have a case if they still trained enough people to service their products, but they don't and the internet has spawned a huge crop of 'experts' who think they can repair anything. If you watch YouTube, you'll see all kinds of building and repairs that can only be called 'cobbled together' and 'Jerry-rigged'. If something is still under warranty, I, as a manufacturer, wouldn't allow someone to repair it without making sure they're able to do it correctly if they want the warranty to continue. Conversely, as a manufacturer, it's up to them to make sure people don't need to wait until hell freezes over or pay an exorbitant price for 'factory-service'.
The way people service their own makes me want to go to them and say 'STOP!!!!!!!!!!!!!!!!! YOU DON'T KNOW WHAT YOU'RE DOING!!!!!!!!!!!!!!!!!!!!!". Wait, I actually do that in a boat owner's forum.
Specific to ski boats (real ones, not just a little boat that kids can ski behind), people who wouldn't dream of touching a $5000 used car dive head-first into their $100K+ boats when something goes wrong, using the 'parts cannon' as their method of finding the problem. These have car engines and because the EPA/CARB and other organizations have made it necessary for the emissions to be low, these are almost identical to what's in a car or truck, including Oxygen sensors and catalytic converters. They complain that their boat doesn't run well, but don't do the maintenance and when they can't figure out where the problem lies, go online and whine about the manufacturer making it hard to work on, yet these same people wouldn't be able to adjust a carburetor or the points in a distributor if their lives depended on it.
