Wait, to be clear, my proposal is that you'd be tipping the restaurant, not the server. There would be no separate line item for the server anymore. You'd be tipping for the overall experience, including the food and etc., at the end of your meal.
And, again, if you didn't pay for the meal, you wouldn't be able to return. You'd basically have to present your pass to a reader and specify how much you'd like to pay, and the credit card associated with the pass would be charged that amount. If you paid more or less than average, you'd get a survey asking you "why?"
It would be kind of like an AP Only Lounge, with a "free" buffet and etc., in EPCOT. We already kind of had that but it is sponsored, and only snacks were served. So, it's not *that* much of a stretch.
To be honest, if Disney offered that, I'd totally go. And I would gladly pay for it. I bet a lot of Passholders would. Rather than constantly squeezing us for more money for less, wouldn't it be wonderful if Disney actually made an effort to give us good value? Yeah...it'll never happen.