I don't buy the notion that it is innate for some people at all

This doesn't pass the real world experience test.

I think you should never feel ashamed of your voice. . . Don't be put off by others or by the thought of what they might say.

I'm not put off by other people, and I'm not ashamed of anything. I sing all the time, just not on stage. There, I'm put off by myself, since I have a pretty good ear and I know what singing in performance is supposed to sound like.

Not being able to reliably sing in tune is one of the great tragedies of my life. Listening to people tell me I CAN do it if I just try is another. All you people who can sing need to get past the idea that anyone can do it.