i blame lawyers in general. the more subjugated a customer is, the cleaner their interaction is with contracts, and the less money is spent on lawyers working through the specific situation. Especially relevant in the event of tragedy.

"your car exploded? well you didnt use a triple certified dealership for your last oil change so you cant hold us accountable for that. says so in the contract."

now obviously if a car had that level of danger.. you wouldnt even be able to get the oil change done anywhere but the dealership. and in modern times where we try to hold companies responsible for everything we possibly can, it makes sense that anytime there is a remote possibility of liability, they attempt to gate the customer out of it completely.

i feel like the general population has either grown to be, or always has been, so indifferent towards subtle legal differences that we continue broadening the strokes of liability which is causing us to lose the power to do many basic things ourselves as a trade off for avoiding any personal responsibility tied to the consequences of doing those things improperly.