Yes, like tobacco, it is one of North Carolina's proud exports. I live in NC, and Krispy Kreme donuts are often used for fund raisers, brought into offices, there are little shops everywhere and they are in all the grocery stores.
As junk food goes, a hot fresh plain KK donut is good, but hardly worth the totally worthless pile of calories.
NC is one of the fattest states in the US of A, so their popularity may be related to that fact.
Stay far away from them, although you may want to try one just to see what they're like. Hopefully you can get a fresh one to maximize the experience.