"If I buy something, I have the right to expect to be able to have it serviced or repaired by whoever the hell I choose"
I agree completely. Of course, it is then my responsibility if I choose to have my equipment repaired by a cowboy outfit and have it damaged or destroyed. That's why it anyway pays to spend a bit more to have services done at a reputable shop with a good track record, and that's why many manufacturers of other products provide training and certification for repairs.
Then it's completely a consumer choice to have their kit repaired by the manufacturer for an exorbitant fee, by whoever is the cheapest with all the risk that entails, or by a reputable and possibly certified shop that might not be the cheapest option but are certainly cheaper than the manufacturer.
To take the vehicle analogy, for basic service or to fit new tyres etc I take my bike to the local mechanic. If more 'serious' work needs to be done, I go to the 'official' garage.