It's true. I have learned, the hard way, that the cultivars of our good heirloom and native varieties don't perform like the originals. The cultivars are short lived and don't attract pollinators. All the good stuff has been bred out. Essentially, the buyer is paying for a double bloom or a yellow coneflower. apis is right. Plant breeders are just trying to corner the market on a novelty that will sell plants. That's why many roses don't have a scent. It has been bred out of them.
apis also said something that has me thinking. "So when you read in a certain bee plant book that a plant is attractive to bees for pollen or nectar. The seeds or plant from the local nursery, in a lot of cases because of modification are a different plant. In a lot of cases not a useful plant as a food source for bees." Hmmmm.
Have you ever compared notes with a fellow beekeeper that says his bees love a particular honey plant? And you think, "I never see my bees work that plant." I have heard and thought that a dozen times. Perhaps plant breeding is the part of the problem or my bees might have something more desirable to work. Something to think about.