I'm going to offer my rebuttal and then be done as we are getting way off topic.
Cedar Fair views the following parks as destination parks and have stated as such in their quarterly release: Cedar Point, Knotts Berry Farm, Carowinds and Canada's Wonderland.
Worlds of Fun, Valleyfair, Dorney Park, California's Great America, Michigan's Adventure, Kings Dominion, Kings Island all depend on the local markets for revenue.
Each of the parks rely heavily on the local workforce to man the parks (with the exception of KBF). Their schedules all reflect this as most will be down to weekend only starting next week and the others will be down to weekends after Labor Day.
SDC is a destination park because it's in a destination area. While not as big as SoCal or Orlando it is on par with Pigeon Forge / Gatlinburg. Their pull is the states you mentioned and many more. There is always an influx of LSU fans, kU fans, and even farther away. Visit a show once in awhile and when they do the "where you from" portion you'll be surprised how diverse the crowd is.
Like I said, it's a mid-tier destination park. I think we suffer from being too close to SDC to notice this fact.