Maybe its just me but it feels like DVC is overtaking everything. And soon non DVC members will be edged out. Enough building DVCs with existing resorts. Y&BC never needed it, now its a crowded eyesore. I stayed there a few times before DVC arrived there. Now, that's one of the last places on property I'd book.
Contemporary used to be a really cool looking building and now with BLT, looks silly. Getting rid of the other garden wing is in effect stopping anyone from staying at the resort for which that was a more affordable option. Then there is no other accomodation except for the pricey tower. And I'm sure prices on that won't be lowered.
I shudder at the thought of DVC coming to Poly and overcrowding that area. Its nice as is. Making 20 more longhouses will just ruin it.
But if they want to build a new, non attached DVC, its no skin off my nose. I'd prefer it. I know many will disagree but just like everything else it will get oversaturated and people will realize its not worth it. Its basic economics. The less you have the more people want them. The more you build and the more overran it is, the less people want to spend their money on it. Its still new enough that people haven't tired of it yet.
I wish the money would just be spent on the parks. There are all of those empty Epcot pavillions that need fixing. There's a great deal that would probably bring more visitors in that way than DVC.
I think the point that you're missing, though, is that Disney has a HUGE pool of people to attempt to turn into DVC owners. Think about how many people visit WDW each year. Now think if they turn just .01% of those people into owners. That doesn't take into account people that buy in that don't buy during a trip to WDW, either.
They'll keep building as long as people buy. Which I'd bet is YEARS, still. Disney's ROI when they put up a new DVC building is nothing short of astonishing. Someone on another board had added up the total points available for purchase in the new BLT and calculated that Disney stood to receive $700,000,000 by the time the points were all sold.

I have no idea what it cost to build that building, but it wasn't even CLOSE to that amount. Add to that the fact that the DVC owners then also pay to run the building for the next 50 years... Of COURSE Disney is going to keep building these things. Massive profit, plus zero cost operation of the facility for the next 50 years?!?!?!? Plus then the members are all very likely to spend money in tickets, merch, food, etc on a regular basis. On top of THAT... Most of these people finance the DVC purchase, which Disney does directly... Meaning Disney then also charges and gets interest from most members, too!!
I believe they'll add small DVC wings to each of the deluxes, because they'll go up quick, they'll sell quick (relatively), and they'll appease guests' desires for DVC's of certain types (like Poly and GF). In between these little add-on wings, they'll work on full DVC resorts at the same time. They'd be stupid if they didn't... That kind of income just will not be ignored. I'd also be surprised if they didn't start adding wings to moderates after deluxes are done, too. Maybe add a different tier or "class". This thing is just getting started, I'm certain.
Debate, if you like, how it might negatively impact WDW... That remains to be seen. Will crowds grow too large? Will they spend on the parks to compensate? Will it create a huge backlash? Will they change DVC perks negatively (as has been rumored) to compensate instead of spending on the parks?? Nobody knows.
One thing I DO know... If you buy in, you better hope and pray they don't change the rules and perks in such a way that would negatively impact the value of the VERY expensive timeshare you just bought.