Their argument boils down to this:
"Proponents of transhumanism, neoeugenics, and human engineering have proposed ideas that would drastically alter society in known and unknown ways."..."The use of genetic manipulations for the purpose of human engineering would have a profound effect on the structure and nature of families and society. "
So let's see here, making us healthier, stronger, and smarter, and extending our lifespans are somehow bad because they're going to change society? Not just "bad", but "crimes against humanity"! Of course they're going to change society! That's part of the point! How can any sane person be opposed to this?
But fear not, my friends! The language of the initiative only addresses genetic manipulation! So while it's a crime against humanity to enhance humanity through genetics, replacing your arms with miniguns and rocket launchers, and installing lasers in your eyes is still A-OK!
*sigh* I have no problem whatsoever with people choosing not to take advantage of any technology that they disapprove of, for any reason. But for those who would inflict their archaic views upon the rest of us in the form of a sweeping ban, I have a two-word response. It rhymes with "truck you".