Human life is precious and needs to be respected. If people design embryos to order, and the embryos don't form into the perfect baby that they wanted, it's quite possible those "failed" babies could be aborted, killed through infanticide, or if they're born, told through life that they are a failure and inferior to the ones who turned out "right". That's just the private sector.
Military applications open up a whole other huge can of worms. There always have been and always will be people with zero ethical limitations. They may decide to design humans with animal features.
They will engineer people to have all kinds of traits it's hard to even imagine right now regardless of the quality of life (or the lack thereof) that this would lead to.