It does seem to make sense - it is the same concept as herd immunity - not every animal in the herd needs to be vaccinated against a disease for the herd as a whole to be more or less protected.
I personally haven't heard the religious crazies ranting about GM foods - I certainly believe it though since most scientific advances encroach on their willful ignorance about the way the world works.
My problem with GM crops is that it is like most things we as humans introduce into our world - we do it recklessly and arrogantly with a "damn the consequences" mentality. It is all profit driven and done in spite of the fact that we have no idea what the long term effects will be. You can't contain GM plants - they cross pollinate. The seeds are patented and cost more - and at least with the corn you can't even save some seed to replant for the next year so you are forced to buy more seed. Obviously the upside of this is plants that require less fertilizer and insecticide, but until we know the real cost of those benefits we shouldn't be so hasty in claiming success. Afterall, we created this ugly spiral with our intensive monoculture agriculture system. That said, I agree that science is awesome!