But it would be bad for Contemporary guests, because that would mean all they have left is the Tower rooms and it would make it harder to stay there. There are sometimes when their rooms are sold out months ahead because of convention groups, so having the Garden Wing helps and that would make it impossible for guests going there on vacation to make a reservation. So I am trying to look at this from a different prespective and I hope you can understand that.
Disney stands to make about $1.2 billion (at today's prices) on point sales for an identical tower. If frequent CR guests are worried about not getting a cash room when they want it, I suspect Disney's response would be to suggest buying into DVC at the Contemporary.

Bottom line is that a CR with three total towers would have quite a few more rooms than the CR did with one tower and the two garden wings.
Also even if they did build another DVC tower one thing they couldn't add is another skybridge to the 4th floor. Looking at where the current Garden Wing building is it would go right into Chef Mickey's and there is no way they would be taking out Chef Mickey's to make room for it.
Again, not exactly a deal-breaker in light of over a billion dollars in potential revenue.