My family and I are DVC members and would absolutely love it if there were a DVC property in the Anaheim area. We have made 11 trips/vacations to Disney parks, 5 of them Disneyland. I've stayed at Disneyland hotel twice, Paradise Pier once and off site twice.
I love spending time on both coasts so to speak and being from Texas a plane ride is a plane ride.
The reality of space is it does not have to be adjacent to the park, just close by. DL has worked for years shuttling people into the park area. In fact consider our DVC properties now and there is transportaion provided/required for all of them. Many of the sites around DL could be suitable for a DVC property. I think the main concerns are the difference in the cost of land.
I also think HH and VB were not as successful because of the lack of access to a park, not just that they were not at WDW.
For what it is worth, I would sure addon at California. I now have BWV, BCV, and OKW and love them all. But it would be a huge attraction to nestle in to The Happiest Place on Earth!