Many breeders will wholesale normals and sometimes hets that are in lesser demand to pet stores. There simply isn't a huge amount of demand for normals (ESPECIALLY normal males) in the breeding side of things, and many pet stores (those that actually care about animals) would rather buy local captive hatched babies that are in good shape and they don't have to pay shipping for, instead of babies from Africa.

Never underestimate normals, though. Simply because they aren't in high demand with breeders, doesn't mean that they can't be wonderful pets. Many ball python owners start out with a normal from a pet store, and they learn how great the snakes are from that.