The discussion is not about "what could've been", much less about "what should we do today". It is mainly about what "would've been if we lived in a world where RMS managed to forbid proprietary/closed-source software". I posit that if this prevailed in the 70's or 80's, there would simply be no software revolution.
> I posit that if this prevailed in the 70's or 80's, there would simply be no software revolution.
And I would claim that you have no evidence for such a statement. Given how much technical innovation happened in the hobbyist computer revolution that predated the "software revolution" (where proprietary software was unheard of) I would argue the opposite. But neither of us can possibly know what would've been in an alternate timeline.
You are right that we can not make a perfectly quantifiable experiment to check the rate of innovation in a "purely Free, RMS-style" world vs the current one where proprietary software is also allowed.
But using that as an excuse to keep believing that "we could have gotten where we are only with Free Software" is a cop-out. We don't need to have an alternate timeline. We can think of our existing one as the (non-linear) superposition of two competing philosophies and their development: the hobbyist/academic/free one & the commercial/private/proprietary/profit-motive-based
one on the other. We can surely come up with some kind of model to see how the "free economy" would fare if there was no "proprietary" agent.
You have said it yourself: there was a revolution going on, but it was only affecting the hobbyists, the enthusiasts. It took the "proprietary" side to exist to make it computing something as universal as it has become.
Without proprietary software, there would be no BSD 4.4, Linus would not have anything to clone for the PC, there would be no Free/Open/NetBSD, and so on.
Remove these from the "software economy" of today, and what would we have? Minix? HURD? "Innovative", alright. But certainly never able to compete with the proprietary (or proprietary-clones) alternatives at any point in time.