If someone pointed a gun to my head and said draw or I will die...well then I'd be knocking on death's door. If a straight line is beyond my ability. Art class was my first B ever. Art out of all things. And she probably gave me a B because of the sheer effort and probably mostly she felt sorry for me.
I used to think the same. But you know what? Drawing is not straight lines.
My approach is to draw a very rough outline and then erase and redraw parts until it looks right. Not very good for drawing on paper, but fair game in digital painting.
And there it doesn't really matter how much of an artist you are, nor even if you have any fine motor skills - just that you're patient enough to keep trying.