This is such a ridiculous straw man! Many inborn traits are not purely genetic. I don't know anybody serious who claims gay people are gay because of simple genetic determination. In that respect, being gay is not like having blue eyes or red hair.

Nonetheless, people who study the matter are pretty sure that genes play some factor, and so do prenatal and perinatal environmental factors.

Blow does nobody any favors by setting this strawman up and then knocking it down.