More importantly, the ability to write and run your own code easily, of which learning is only part of the process. From that perspective, Apple was closed from almost the beginning, while the PC and various other micros of the time (ZX, C64, etc.) started out open.
The Apple ][ wasn't closed, you could hack away on it just as much as any other 8bit machine of the day. I think (correct me if I'm wrong) it was from the Mac onward life got a bit more challenging.
I found the early macos’ (6,7,8 and 9) incredibly frustrating for this reason. Pc users has dos and qbasic, but other than hypercard, mac didnt seem to have a way into the internals to learn about coding. Stuck in userland.
