I very much want this to happen now. However I would not have wanted this 15 years ago when the platform was a baby and little was known on how to move it forward. Last thing you wanted at that time was layers of regulation and laws that would hinder the speed of development.
15 years is probably too long and this could have happened 5-10 years ago.
At that time, Apple's system needed to attract developers, so instead of a walled garden, the company did what they could to encourage interoperability.
[1] http://apple1.chez.com/Apple1project/Docs/pdf/AppleI_Manual....
You are confusing the "norm" at the time, with Apple specific decision to open up their hardware. At the time, a lot of consumer electronics shipped with their schematics, including TVs, Radios, etc. You cannot find a single TV today that ships with how to talk over its diagnostics port let alone schematics.
The Apple computer you're referencing was more like an of IC of today, both in complexity (many $1 ICs today are orders of magnitude more complex than that entire computer), and the skills expected of the user of the computer. Both of which would require one to have intimate knowledge of the inner working of the device to be able to operate and maintain it. Users of that computer were like hobbyist of today, buying an electronics kit and rest assured, electronics kits come with detailed manuals, schematics and more.