I am not sure if
DVC makes financial sense in EVERY respect, but here are a few things I thought about....
I am locked in to MF through the end of the contract......I could use my MF for a hotel booking at a moderate and save the purchase price. But I want the flexibility of staying in a villa with my extended family. All of us together. Sure we could split rooms and meet for dinner. But with a villa, we can do like we do at the beach......hang out around the table......but at WDW and not the beach.....BIG plus.
I want the flexibility of going to Aulani. I want to see Pearl Harbor. For my BLT MF, I can see Pearl one day. My best buddy just dropped 2500.00 on a hotel reservation in Hawaii that is comparable to Aulani. MY MF are $720.00. Sure there is cost associated with travel out there, but the point is, I would incur those expenses AND would have to pay the 2500.00. The value is not necessarily in the difference of the hotel reservation and my MF.....the value, to me is the flexibility to use the points out there.
I want the flexibility of staying in Anaheim in 2015.....we may be going to DL then.
I have assigned value to ownership of DVC. This value is over and above the rack rate/ DVC comparison. I put being on the monorail, seeing the castle, walking to Food and Wine and doing it over and over till i'm 80 at a priority. If I croak before then, then my kids can do it with their family on my nickel. That helps you NONE

.....but I say all this because there are intangibles, like feelings and preferences, that really make the difference in the decision.
Just a thought or two.