For example, should we scorn genetics researchers who do not have a credible claim that their organisms will remain harmless after a billion generations of evolution and recombination? That's more or less what many of the anti-GMO arguments boil down to, that we ought to require genetically-modified organisms to be provably safe, both as they exist now, and in all possible future ways they could evolve and interact with other organisms. (And since that bar is very hard to reach, therefore, their arguments go, we should be careful about funding such research to begin with, and definitely shouldn't let any of its results out into the wild, e.g. into crops.)
If anything, the argument there is stronger, because evolving biological organisms that can pose a threat to humans actually exist, whereas evolving machines that can pose a threat to humans are sci-fi, and likely to remain so for a very long time. Why regulate the latter one more stringently?