It’s not WHAT you share, it’s HOW you share.

As you noted in your presentation, though, the concept of higher education itself is becoming obsolete. Paul Graham noted in his essay, After Credentials, that the purpose of higher education is to certify that a person can do something … but people are increasingly finding ways of judging each other’s performance that don’t rely on credentials, or even ways of letting the market decide directly.

There are people out there right now who aren’t just writing competing textbooks, but creating a world in which there’s no longer a need for textbooks. If your efforts do nothing to help them, but instead forestall the inevitable, you aren’t helping but hindering; both “openness,” and people’s ability to be judged by the marketplace, a process on which higher ed is fast losing its monopoly.

It may be that the most pragmatic thing to do, in iterating towards openness, is to realize that iteration won’t work.

If these textbooks are good enough that people would read them of their own free will, and actually learn things from them, then not licensing them under CC-By-SA holds people back. It prevents the establishment of a competing system of education, which could itself charge for admission / accreditation or even for access to personal instruction.

I suppose the only consolation for such tutors is that most textbooks aren’t worth using to begin with.