Well that is now but wait till political and financial considerations come into effect. I mean if you have to deal with a budget the way your decisions are made will change. For example a person who is lazy or has a slightly increased risk of getting a depression or disease that is expensive to treat will be undesirable in your eyes. Not to mention entire feared ethnic groups.
Eugenics is not only morally bad, it is evolutionarily shortsighted too. Eugenics says for example, that a person born with a condition that prevents them from walking should not reproduce. But then what if that person also has a separate gene that makes them super smart? With eugenics, the intelligence gene is lost. With gene editing the person can fix the walking defect and have offspring such that the intelligence genes propagate.
With gene editing people with obviously bad traits can still reproduce. We won't get any closer to solving the slippery slope issue but as everyone chooses the intelligence genes someone in the future can solve it.