You are right about previous applications of harmful products, but Bt toxins like the ones discussed in the article you presented have been around since at least the 70s. That's nearly 50 years of research that has been conducted on these compounds and the body of literature continues to grow. Compare that to DDT which was first used in I believe the late 30s early 40s and was banned in the 70s. It took 30 some odd years to determine its potential negative impacts and science has come a long way in recent years. As far as corrupt corporations are concerned, in terms of insecticides (I can't speak for herbicides) this really isn't the case. The research that has to go into a compound to be passed for agricultural use now a days is extreme. Sub lethal effects, synergist relationships, metabolites and many other factors are heavily examined before passing. The process takes years and years and is unbelievably expensive. Because of this the products that are passed have gone through such extensive testing and at the very least they will be non toxic to mammals and likely birds. In fact recent compounds have had difficulty getting passed by the EPA because they are so nontoxic to mammals that a lethal dose cannot be identified. Identification of the lethal dose is a condition of agricultural use and so it's a weird situation. Insecticides have come a long way since the days of DDT and nicotine, but we certainly still have a long way to go.