What does it mean to have a "good" voice?

Imagine....

you have just heard an amazing French Horn solo;  impeccable pitch and control, a round and full tone, moving flawlessly between notes and creating a sense of emotion and intention.   Would you say,  "Wow you have a great French Horn!"  No.  Most likely you would say, "Wow, you can really play that thing."  But we tell good singers, "Wow, you have a great voice!"   I have noticed that the better vocal shape I am in (practicing every day and in good vocal health), the more often people say, "You have a great voice."   So what makes a Voice, 'Good'?   There are certain anatomical traits that do play a factor, but more importantly, a solid TECHNIQUE, a refined sense of LISTENING and a developed ABILITY TO CONNECT the voice to intention and emotion will maximize the potential of YOUR FRENCH HORN...er, I mean VOICE.