I don’t know why you bring up 17 U.S.C. § 117(a)(1); it is completely irrelevant to your question. It is an important thing to understand, but it doesn’t have any effect on the answer to the question you asked. I can’t even fathom why you would think that it does. Maybe it is some kind of motivated reasoning?
The FAQ is, however, quite relevant. It’s certainly not part of the text of the GPL, but your Question is very Frequently Asked, and thus the answer to it is right there (<https://www.gnu.org/licenses/gpl-faq.html#MoneyGuzzlerInc>).
I'd like to modify GPL-covered programs and link them with the
portability libraries from Money Guzzler Inc. I cannot distribute
the source code for these libraries, so any user who wanted to
change these versions would have to obtain those libraries
separately. Why doesn't the GPL permit this? (#MoneyGuzzlerInc)
There are two reasons for this. First, a general one. If we
permitted company A to make a proprietary file, and company B
to distribute GPL-covered software linked with that file, the
effect would be to make a hole in the GPL big enough to drive
a truck through. This would be carte blanche for withholding
the source code for all sorts of modifications and extensions
to GPL-covered software.
Giving all users access to the source code is one of our main
goals, so this consequence is definitely something we want to
avoid.
More concretely, the versions of the programs linked with the
Money Guzzler libraries would not really be free software as
we understand the term—they would not come with full source
code that enables users to change and recompile the program.
This is a legal question. The statute, which is a legal authority, is absolutely relevant. The FAQ, which is not a legal authority and not part of the license and not even published by any relevant party, is absolutely irrelevant.
The FAQ is, however, quite relevant. It’s certainly not part of the text of the GPL, but your Question is very Frequently Asked, and thus the answer to it is right there (<https://www.gnu.org/licenses/gpl-faq.html#MoneyGuzzlerInc>).