It's the same arguement against cloned meat. People get upset by the method because they don't understand that the DNA literally doesn't care.

If you modify you through breeding or through direct genetic manipulation or even through radiation exposure, Which is how they got red grapefruit by the way, the end result is still DNA. It's not weird mutant dangerous DNA, it's just normal DNA which is different to the original. There's no way it can hurt anyone.