So they are introducing all sorts of new viruses into the dance of life with no clue as to the consequences they will have on the environment and us and our animals etc.

This right here is the simplicity of the argument. It's untested. Most people either don't know GMO's are so rampant, or they bought that it's no different than hybridization.

Just like the doctors in the 1950's who told the public which brand of cigarette they preferred didn't know the effects of smoking until decades later, no one knows the effects of genetic modification either. Unlike the consequences of discovering too late that smoking is bad for you effects only the smoker, discovering genetic modification is bad for you effects the world indiscriminately. And by then, it could be too late to do anything to fix it.