[troutmskreplica]

If you bought a PC-compatible clone in the 80s you had a good chance of being able to find documentation of some kind to tell you about how pieces of the hardware itself worked.

Not at all the case for other kinds of hardware, or any software.

Companies being required to release documentation would increase the cost of development (passed on to the consumer) by a non-trivial amount.

As it is, people inside companies usually cannot get good documentation for the things the company develops that they need to interface with. Been there, seen that. It’s unfortunate, because that can also increase costs, but usually people just muddle through with poor documentation and many email chains to ask questions about the things that are poorly documented.