There are two main arguments against genetic engineering, the first is that it is unsafe, and the second is that it is immoral. The first is staying the way it is due to people complaining that it is unsafe. The second is rather strange considering non genetically modified people do not get to choose their biological future either.
“One popular argument against the human use of cloning and genetic engineering for reproduction is that these procedures are not “safe” and may result in the birth of children with severe developmental abnormalities.”
Habermas J. The future of human nature. Cambridge, UK: Polity, 2003
” Reproductive cloning violates the child’s right to an open future.”
Davis D S. Genetic Dilemmas. New York: Routledge, 2001