Even without the author's counterargument the assertion that one's genetics is an unfair advantage strikes me as absurd. Your genetics is not something you've got, but literally a part of what you
are. Questioning whether one deserves to be oneself is like asking what's north of the North Pole - just because you can put these words together in a sentence doesn't mean it it makes any sense. Furthermore, intelligence is not a "good" in itself. You earn ("deserve") goods by being useful to others. If a "gifted" individual invents a technology that makes life more comfortable for the unintelligent, does he not deserve a reward regardless of what enabled him to do so?
On a different note, I don't understand how anyone can consider equality of outcome desirable, regardless of whether it's achievable or not. If your outcome is guaranteed to be equal to that of others then it by definition doesn't depend on your own choices. If it's not the ultimate unhuman antiutopian existence I don't know what is.