This isn't "my approach" – it's the approach that the vast majority of purchasers prefer. And pining for the good ol' days of technical datasheets doesn't help everybody who can't start their cars without the successful interaction of nearly a hundred proprietary microcontrollers running proprietary code speaking over a high-speed data bus.
And here's the annoying thing: I want a car that doesn't have a hundred microcontrollers speaking over a high-speed data bus. I want a car like my old '88 Camry, that I could take apart with my dad and fix almost all of the problems I ran into with the help of a Haynes manual and a trip (or two!) to the junkyard. But the market clearly does not agree with my desires.
So how do you get there from here?