From the people I've been speaking with in the electronics industry, when you purchase ANY type of gadget that has a proptietory computer program installed, you're really only buying the right to use it, you're not technically buying the entire gadget outright. Patents & copyrights protect the proprietary programs installed.

Combine this fact with the price of the electronic diagnostic tools needed to diagnose complex computer systems installed in equipment today & the answer will be that only dealerships will have the authority & the information needed to service their brand of equipment.