I may be missing something, but Universal isn't taking those rooms out of inventory to sell them and lock customers in for 40+ years. If you think the two are remotely close to each other, then I don't know what to tell you.
They are actually more similar than you think, in some respects.
My DVC ends up running me, if you cost it out in a pretty basic way, about $160 a night for a 1 BR. That's, functionally, two deluxe "bays". I understand why they're doing it...because they get the up front buy in that they can invest, and make opportunity money on over 50 years, AND my dues make them additional profit via administration. It's sunk money they can count on, and there's no variability. They can also veritably count on my ticket money to the parks.
Your assertion is, basically, Uni can't be making a similar, if more short term, attempt at pulling in money other ways, or attempting to lure in new business. That is HAS to be occupancy fueled.
While simultaneously making the OPPOSITE assertion...that Disney choosing to convert already built out facilities to DVC MUST be PURELY a profit driven decision, and not have anything to do with occupancy.
If YOU can't see the similarities, or the juxtaposition there, then...I agree...YOU don't know what to tell me.
I'd offer that the conversion of already built out facilities to DVC is BOTH a way to deal with an occupancy issue AND a way quick way to fuel more DVC profit. It was with Jambo house at AKL. It likely is with WL, as well.
Someone asked which Disney would prefer: Hotel booking or DVC conversion? They'd PREFER, given the rooms are already built out, to rent those rooms for the going hotel room rate for the next 50 years. If that resort were 100% occupancy, and trends showed it would stay that way, they wouldn't be converting...because converting means spending MORE money on something that already exists, and, actually, is more than likely paid for (considering when WL was built).