Agreed. Not much milkweed grows in corn fields, although possibly next to them. Destruction of milkweed habitat occurs more via development of open fields and meadows, for housing and commercial development.
The last paragraph is also unnecessarily pejorative and shows biased responses to what should have been an in-depth study. Also no mention of newer, targeted gene-transformation processes that promise to be very beneficial and should not be lumped in with the earlier processes.