Since we don't own, we are renting a room that might otherwise be unoccupied. So I have to think that's a better position for the resort than the room(s) sitting idle.
Not at all from Disney's point of view. If that room sits idle and unoccupied, Disney can rent it out through CRO for cash. If they don't do that, they can upgrade a cash CRO guest whose marketing profile looks like a good candidate to buy into that DVC room. At the very least, it sits empty - which means they don't have the variable costs involved with occupancy - such as cleaning it. But the hope is that if you don't rent a DVC room, you will book a cash room through Disney. And if you don't do that, then you will book something offsite - and Disney will still get the cash they would have gotten from you as a rental (probably a little more since you'll end up paying for parking). They only "lose" money if you decide you aren't doing WDW at all - and even then, they haven't been having attendance issues and fewer people in the parks has some benefits. I don't think there are many "I rent DVC points" guests who are going to make "I can't get a room through rental" the tipping point in going to Disney - and a certain number of the guests that will are so price sensitive that Disney would rather have them not taking up room in line in favor of guests who are less price sensitive.