I eat in the park, but it has to be small, at the most, a half a Chik-fil-A sandwich, because rides. I don't go there for the whole day. I usually hit the park in the afternoon. I never eat before Diamondback. That's just not done. To me, the prices are comparable for the convenience of staying in the park, not hauling out to the parking lot and driving. The up price at KI is basically a convenience pricing, but the up price at Disney is for the fantasy.
Cedar Faire plunks down a roller coaster any old where, and we whoop. They don't have a theme besides 'amusement park'.
Disney paints everything fancy and holds it all together with a cod pin. That's what people pay the extra for. There's a perceived idea of perfection you pay for at Disney (maybe that's why people like Katiebug get upset- throw her in KI and she'd think she was lucky that someone didn't eat before they rode Diamondback).
And when comparing prices, think about this; I was a ride operator at KI, and my mother was the hoser at the Viking Ship.