You sorta slipped in "and AP holders" in the end there making them just like DVCers... and they're not.
AP holders who run into the parks at night after work to see the fireworks eat at home or locally. The Kentucky family spends money for all their meals in the parks.
AP holders who drop by weekly are only paying $20 per visit over all compared to someone who pays $100 for a day-ticket (more if you include the hopper benefit the AP gives).
AP holders with no blackout dates pop in during the peak holiday times and make the parks even more overcrowded, which impacts the vacation of the once in five years family.
The once every five years family doesn't have park warfare down to a science to know how to hit all the rides. "Sorry kids, Space Mountain was a 90 line and we didn't have time for it." Meanwhile, APers don't mind not hitting every ride every visit because there's always next week... or the next day, or the day after that.
If the once in every five years family winds up not having a good time in an overcrowded park, they tell everybody they know and it hurts the brand and discourages other possible once in every five years family.
And back to the premise that DVCers spend money in the parks for all their fine dining meals.... The DVC suites have kitchenettes, no? I've seen plenty of DVCers in these forums talking about buying groceries and preparing their own meals.