Earlier quoted context omitted.
That's because the Apple II+ was produced in an age where the inventors of computers envisioned everyone learning to program computers...as opposed to using them as really expensive fancy typewriters, which is essentially what most people use computers for today.
The only person who has ever had that vision, consistently, is Alan Kay. The Apple was programmable because it was made by hackers for hackers. There were a few firms that would do software consulting for corporations and institutions, but the notion of consumer software barely existed. Apple didn't mind it if a few people wrote third-party software and sold it. But I think in the beginning they expected to provide a…
Don't forget Ted Nelson, whose book (which I bought YAY :D) Computer Lib/Dream Machines features the slogan, "You can and must understand computers now!"