Krackel, as you might know, is a chocolate bar from Hershey that only ever appears as one part of the foursome of tiny treats that comprise a bag of Hershey's Miniatures (the others are standard Hershey's milk chocolate, special dark, and Mr. Goodbar -- which sucks-- all of which are available on their own). I have never seen a Krackel bar sold by itself, nor have I ever seen any advertising propounding its merits or explaining its limited availability. According to Wikipedia, the Krackel was born in 1938, but it doesn't say when it was retired, or died, as the case may be. Something happened to it, because it certainly doesn't appear on Hershey's website among its cousins.
The Krackel bar is made out of milk chocolate and crisp rice, similar to the Nestle Crunch, but for some reason, far superior in taste. Whether this is because of some secret recipe, or the proportion of crisp rice to chocolate, or simply because Hershey's chocolate is better, no one will ever know. What we do know is that Hershey makes it difficult to satisfy a craving for Krackel, while Nestle Crunch bars are in abundance, much like boils during a plague.
I guess we must assume that at some point Nestle and Hershey went head-to-head on the highly competitive crisp rice chocolate bar market, and that Nestle emerged with such a definitive victory as to establish a complete monopoly (see Beta vs. VHS). Hershey must have limped away with its tail between its legs, and chose to discontinue the bar rather than suffer through the embarrassment of smaller market share and general inferiority. However, they must have also been determined to keep the Krackel alive in some form, even if only to diversify an assortment of its more successful chocolates. But why this half-hearted commitment, Hershey? You clearly have no faith in the product. Is the elderly inventor of the Krackel blackmailing you? Or was it the dying wish of one of Hershey's original chocolate engineers to keep his brainchild going in some form? Or do you just have to get rid of all that crisp rice that you bought during the Depression?