Author here. You're right, and it's a better version of my point. The shaft persisted because small high-torque motors weren't economically feasible yet, not because anyone was blind. That's the structure I'd argue we're in now: the constraint isn't ignorance, it's that the enabling piece isn't cheap enough yet.

My claim is that for knowledge work that piece (capable models on hardware you own) is crossing into feasibility right now, which is when, by your own account, reorganization actually happens fast. "Why would they" was too glib; "they couldn't yet, and then they could" is the real shape. Fixing that line.