no, you could very easily clone the Apple II easily and it was done many, many times
it's true that eventually Apple started suing people, but until Apple vs Franklin it was unclear if you could even copyright a BIOS. And once that was determined, people had to clean-room reverse engineer the BIOS but it was possible to make clones (see the Laser 128 and many many others)
this is just as open as the IBM PC was. You couldn't just drop a copy of the PC bios into your clone, you had to go to a 3rd-party reverse-engineered BIOS
Even more, Apple tried to block the Laser 128 and failed, since VTech didn't actually do anything illegal; they reverse engineered the Apple APIs and licensed BASIC directly from Microsoft.
They were actually pretty cool computers; half the price of the name brand Apple while being mostly fully compatible with all the software. I've only played with one once, but I thought it was pretty cool. Sad that VTech only makes crappy kids toys now.
The key was that by publishing the BIOS source in the open, it was hard to prove that you weren't exposed to the source code when you wrote your own BIOS.
The clean-room approach was a neat hack that solved the problem, but it was hard to find people that had never seen the IBM source and could prove it.
Just like posting source code does not make the code open, publishing schematics does not make the design open.