If I were to create an AP available for locals, designed to prevent abuse it would be the following:
14 anytime visits a year, no park pass reservations needed.
But how would you prevent them from all going on Saturday?
Besides, this is really about TWDC happily taking the money for the APs but really not wanting APers in the park.
Of course they want APs in the park. Having the extra revenue on days when the ticket sales are slow, is a win-win for everyone. People get cheap admission to the park, and Disney gets to sell overpriced churros to the masses.
What doesn't work is when your discounting program to bring in extra people on slow says, starts dictating when and where your slow days will be. When things shifted, and Saturday and Sunday became the slowest days of the week, they knew they had a problem. When Cast Members were forced to park at Angel Stadium on the Monday in August that the So Cal APs were unblocked, is when they realized they had a problem. When the regular ticketed tourists started complaining about how crowded the park was, and threatening to go less, while Disney chased the discounted admissions, was when they had a problem.
They've used blockout dates to try and force the market at large, to change their habits and visitation strategy, and from introducing the blockout dates in the 90s, adding AP tiers, fiddling with park hopping and all the way up to the reservations, they have failed to control it. Like Frankenstein's monster, the AP program is still out of control. Removing the reservations would be disastrous to the system.
My guess is, after this lawsuit, they will slowly start to eliminate the concept of the blockout date, and work to make the reservation system clearer and more fair. But the reservations aren't going away.