Great question. I've always wondered why people who believe the great scientific minds are correct about global warming and the risks of low level pollutants don't believe great scientific minds when they tell us that genetically engineered foods are safe.
I still have nightmares about my airbag killing me in my daily commute, but at least I don't worry about white guys in white vans sniping me at the gas pumps anymore.;-)
That IS my point. I'm generally surprised that people on the Right -- who tend to have a little more faith that, with persistence, you can push something to the point where it works -- don't feel the same way about technologies that solve problems that they don't necessarily agree ARE problems in the first place.
The leftists who see 'danger' in genetically engineered foods are only upset that it's Big Corporations that are doing it, and they will not have the wherewithal to do the same, or that some diabolical corporate scientist has left a time bomb in the gene...it's a political opinion, not a scientific one. Rational skepticism is reasonable, but like you said, after some point, an honest skeptic would accept favorable results. They don't. The Jeremy Rifkins of the planet just stubbornly refuse to give in, even when confronted with good results. Are the results imperfect, incomplete? Probably. But if you want perfection....ain't gonna happen.
Over the last 30 years I have heard time and again that this was a big problem, never happen, too hard, too expensive, blah blah. Engineering curricula mentions this in many places, but also provides rational tools to debunk the repetitive erroneous assertions. But consider some of these famous statements:
Theodor Von Karman, 1921: "The Gas Turbine will never be light enough for aero propulsion, even if you could make one work". Wrong.
Ken Olson, Head of Digital Equipment Corporation, 1977: "What could you use a personal computer for except maybe balancing your checkbook?" Ken's gone. So's his company.
The world to Stan Ovshinsky in 1978:"Amorphous Semiconductors will never be economically viable". Do a web search on Stan for some history. They were wrong.
You just gotta keep trying. If there's a real goal, and you aren't trying to build perpetual motion machines, you never know. You just might get what you need.