The same would apply not only to software, but all copyrighted/patented objects. Surely you don't advocate forgoing those, so why is software different?
Most of the arguments for Free Software do not apply to other copyrighted/patented objects, but it's still worth considering the analogy.
Many of the books studied in schools are copyrighted and deny the freedom to distribute (Freedom 2), or to distribute modified versions (Freedom 3). Books aren't the same as software though. Unlike a book, software does stuff. It can act against your interests. There are many ways proprietary software can be harmful, [0] few of which apply to non-Free books.
It's the same reason the FSF have a strong position that game engines should be Free Software, but they aren't too concerned if game assets (maps, textures, music, etc) are paywalled and non-Free. A texture can't do harm in the way executable code can (not counting malicious textures that exploit security vulnerabilities).
(Incidentally this is the current licensing situation for DOOM and Quake. The engines are Free and Open Source Software, but the game assets are paywalled and non-Free.)
Studying patented technologies might not always be a mistake, as it may represent the state of the art, and still be worth studying. I believe the NOTAR helicopter technology is patented, for instance, but it's still worth teaching to aeronautical engineering students. [1] Again, the issues there aren't the same as the issues with non-Free software. The issue of companies paying schools to teach their solutions, is a different matter.
What worries me is who's going to bear the torch when Stallman is done. Yeah I understand that he is mostly a notional head now, but cant imagine another person with a comparable voice and reach.
Time will tell how well the new guy, Knauth, does. [0]
The easy bit will be to not repeat Stallman's faults. Stallman would often come across as pedantic and combative in the Q&A session at the end of a talk, for instance, and would say absurd things such as that people who make proprietary software should be imprisoned.
I think his absurdities and hardlines were a necessity. Had he been more amenable to compromise I doubt FSF would have been able to push the agenda into that tiny sliver of mainstream that it managed to.
Many of the books studied in schools are copyrighted and deny the freedom to distribute (Freedom 2), or to distribute modified versions (Freedom 3). Books aren't the same as software though. Unlike a book, software does stuff. It can act against your interests. There are many ways proprietary software can be harmful, [0] few of which apply to non-Free books.
It's the same reason the FSF have a strong position that game engines should be Free Software, but they aren't too concerned if game assets (maps, textures, music, etc) are paywalled and non-Free. A texture can't do harm in the way executable code can (not counting malicious textures that exploit security vulnerabilities).
(Incidentally this is the current licensing situation for DOOM and Quake. The engines are Free and Open Source Software, but the game assets are paywalled and non-Free.)
Studying patented technologies might not always be a mistake, as it may represent the state of the art, and still be worth studying. I believe the NOTAR helicopter technology is patented, for instance, but it's still worth teaching to aeronautical engineering students. [1] Again, the issues there aren't the same as the issues with non-Free software. The issue of companies paying schools to teach their solutions, is a different matter.
[0] https://www.gnu.org/proprietary/proprietary.en.html
[1] https://en.wikipedia.org/wiki/NOTAR