My concern was with several cultivars that specifically produce non-mammal-safe pesticides, but are intended to produce them only (or primarily) in non-edible parts of the plant. There are lots of pesticides we absolutely shouldn't eat, and there's been some controversy over whether specific strains (of corn, largely) keep them at safe levels in the edible components of the crop.

I don't mean to imply general opposition to pesticides, just very specific combinations of pesticide/crop/cultivar.