Donatello's known homosexuality did, I am convinced, played a major role in his final creation.  It was common knowledge that Donatello was homosexual, and the femininity of the statue and its pose reflects this.  The masculine nature of many of the marble depictions were against the common ideal representation of David. In the story of David, it is a boy who defeats Goliath.  This one of the biggest reasons many people, not only the Medicis, commissioned such youthful depictions. There was more of a controversy surrounding the fact that it was the Medicis who commissioned the work rather than the homosexual nature. Homosexuality was far more excepted and less controversial in that time when compared to today.