I've heard the "dealer support" comment/argument a lot over the years. My experience is that you can count on your local dealer to order/sell you parts and that's about it. I've taken 4 saws to 4 different Stihl dealerships, and was told the same thing every time. Cheaper to just buy a new saw. For reference, that would have been somewhere between $700 and $1,600 depending on the saw. None of them ended up costing me more than $100, and one of them just needed a new spark plug. I thought it was a carb issue, and I didn't have time to mess with another @#$%@#% ZAMA carb. Dealer told me that the top end was shot, no compression. Did a compression test when I got home and it was 150psi, which was exactly what the compression was when I bought the saw almost a decade earlier. Plug looked like crap (same plug that was in it almost a decade ago), and it's been running great ever since.
Dealerships have to meet a quota to keep their dealership status, and the OEM normally wants to increase those quotas every chance they get to make the share holders happy. Also, dealerships don't generally pay technicians enough to raise a family on. So you either get a young (inexperienced) tech, or some guy who isn't technically competent enough to make more money doing something else. So at most dealerships, they can bolt on a new carb and tune the saw, install a new air filter, and replace an oil pump and/or clutch, but that's about it. On rare occasion, you find someone who makes their money somewhere else or some other way, and works on saws because they WANT to. That's the guy you want working on your saw, whether they happen to work for an OEM dealership, or out of a shed in their back yard. And while I'm on this tangent, automobile stealerships are not all that different. Read the code, look the code up in the book, replace what the book says to replace, charge the customer what the book says to charge. Gone are the days of being able to expect the ordinary person to THINK. So, if you REALLY don't want to turn a wrench on your saw, or get hosed by a dealer, you might want to stick to battery powered saws....