From what I remember in psych it IS instinctive, we think of it as ear candy now, because the job it use to accomplish is no longer needed, and if I remember correctly that was to ward off potential threats, hence the reason a lions roar is so deep, it also is ear candy in a psychological way, because it is the opposite of a woman's.
I don't have a deep voice. Luckily I have other attractive qualities...I hope.
Also I think a deep voice on me would just look wrong. But then again there are people whose voices don't match their bodies/looks if you know what I mean...