This! Exactly the targeted guests that Disney is counting on with the DDP option! Our DS & family feel the same way, even though they would never eat all that food, especially all the desserts.
We, on the other hand, never eat desserts or sodas with our meals, nor do we eat that much food in a day. We have saved our receipts, and the total is about 1/2 the cost for the DDP on our 10 nights there. That's eating what/where/how much we want, but paying oop, and not worrying about the cost.
Sure, for some families and their eating habits and # of children on the plan can come close to breaking even, or better, with several character meals, but with the expensive meals (even on plans) also comes the expensive tipping. So, it's definitely not one size fits all - a lot of people are in the camp of wanting 'convenience' and that's what Disney is counting on!!
I'm just too practical/logical, to trick/fool myself/whatever into accepting the fact that it's already been paid for so the price/cost of the meals really don't matter. Paying is paying, no matter when it was done.