That is true, but we also didn't have the vast variety of farm raise crops in this country to pollinate then either, nor a customer to sell it to. Man is Earth's worst enemy, we import creatures to pollinate crops, build an addiction to their pollinating skills, then kill them with parasites, diseases and unknown threats like CCD which I'm sure we will find that we are also responcible for.
I still think it may be a reaction to the commercial food sources bees are fed, is it really part of their dietary needs - dogs can live off of vegitables, maybe not enjoy it, but they can live off of it - cats cannot. Even if the veggies are 100% flawless and vitamin filled, you still end up with a dead cat. Could commercial beekeepers be their own worse enemy? The CCD problem surely seems to hit commercial operations greater than backyard beekeepers.
Just a few thoughts.