This is an area I know a great deal about... and these are thoroughly expected results.
The primary goal of GM crop development has never been to increase yields, or (and this may be a better way of saying it) if GM crop development has been about increasing yields, the ways that yields are to be increased are completely constrained by the desire to maintain proprietary control of the product, in the case of the Bt varieties of cotton and corn, and to foster/increase the sale of other products, in the case of herbicide resistant varieties of soy and maize. The secondary purpose, but primary claim, is that Bt-varieties will allow growers to reduce pesticide inputs and herbicide resistance will decrease competition for soil nutrients and, presumably therefore, increase yields.
The fact that Bt-corn varieties intended to deter Western Corn Rootworms were almost completely unnecessary. The "problem" that was to be "solved" by Bt-corn was that WCR resistant to first generation pesticides (chronic toxicity, long ecological half-life) AND second generation pesticides (acute toxicity, short ecological half life) had been controlled - since the late 70s - with corn-soy rotations since soybeans are a viable host for rootworms only once mature and corn are great hosts whose maturation runs parallel to the development cycles of WCR. In the early 90s, however, it appeared that - in under selection pressures believed to run parallel to those which generated pesticide resistance - the WCR had evolved a "behavioral variant" that was responding to rotations by "anticipating" that corn would be planted in soy fields the next spring (WCR eggs overwinter in ag fields before hatching in the spring) and were laying their eggs in late season soy fields.
Since the WCR was resistant, or effectively resistant, to all legal pesticides the "only" available solution economic entomologists, Monsanto and the Farm Bureau could see was the use of new GM technologies to make GM corn. Unfortunately, 1) they completely misunderstood the problem and 2) there is already extensive evidence of Bt-resistance among WCR populations... -
What they misunderstood was that the problem was that, given falling grain prices, farmers sought out cold-hardy varieties of corn that could be planted in icky, mucky soils on a schedule that allowed the farmer to continue the kinds of off-farm employment necessary for surviving as "farmers." These cold-hardy varieties, however, unlike their predecessors, matured out of sync with WCR. Under these conditions, dessicated corn arrived in August before egg-bearing adult WCR beetles were ready to lay their eggs. Since the beetles are capable of flying distances sufficient to cross Lake Michigan, if not farther, beetles would fly to, consume and lay their eggs in more attractive fields... but, in the areas where this was a problem, the only other moist fields with attractive plants were soy fields to be planted in corn the next spring...
So... the first problem was that farmers were selecting cold-hardy varieties that no longer synced up with the WCR lifecycle and the second, but actually prior, problem was that this happened in agricultural landscapes simplified to the point that (for all intents and purposes) only corn and soy were being grown. (The place where the WCR "behavioral variant" was a major problem was primarily the super-simplified agroecologies of central Illinois and the boundaries were largely associated with the edge where this terrain met more complex agricultural systems.) Under these conditions, Bt-corn was completely unnecessary, even if it was the only option that could be imagined by reductionist entomologies, conventional and pluriactive farmers and agripharma corporations.
Two alternatives would have "solved" the problem w/o transfering so much money to Monsanto et al or generating Bt-resistance. The first would have been to seek out cold-hardy varieties with lifecycles in sync with WCR. The second, though much harder, would be to develop agricultural policies that actually foster even incrementally more diversified agroecological landscapes.
I love the UCS but the depth of they could use to have a great deal more in the way of integrative social and natural science.