I agree it is resilient, but that resilience has been tested by a slow, small increment evolution over millions of years. And even given that, genetic disorders with novel expressions exist that confound modern science. if we start making very fast changes, the resilience of the genetic system shouldn't be expected to hold up against a far faster change rate. And more to my point about the complexity of it all, there are huge regions of our genome that we thought were "unrelated" to human phenotypes (physical expression of genetic code) until very recently when we discovered some of this "junk" DNA actually is critical for certain types of RNA transcription / repair.

GMOs are a different issue. My underlying concern about the influx of new genes introduce to the wild quickly being potentially dangerous aside, the genetic modification have mostly been to make plants resilient to various herbicides/fungicides/pesticides to allow large scale monoculture farming. That's one solution, but not the only. And we have seen invasive forms of GMO crops spread out of containment, thus entering the wild population, and we wont know the consequence of that for a long time, if any.

takeaway being, its probably worth being conservative about even moderate scale genetic manipulation of any species we rely on, and especially our own genome. Not saying dont do any genetic modification, just that it really has to be air tight, you might say NASA level standards of engineering. Now, you tell me if you think Monsanto's engineering standards are at NASA level, or that the Chinese Governments ethical standards are without problems.