Obviously an AP discount doesn't fit every
DVC owners' needs, but IMHO I think that it fits the majority. Keep in mind why DVC offers park admission discounts...to get people into the parks spending money on food and souvenirs. An AP discount possibly gets people into the parks more often than they would with a daily pass. At least, that's what it did for us. Would you go to the parks more often with a discount on daily passes?
If you are going 8-10 days a year with split trips, can't you time it so you are taking three of the trips in a one year period and therefore getting 14-15 days out of the AP? If you could, the AP would be very worthwhile.
Besides, the AP is an entry into other discounts like DDE and room cash discounts.
If I have a choice, it's AP all the way vs daily park tickets. But again, I can see where that wouldn't benefit others as much, especially those who only go for a week every couple of years.