I have been drawing since I could pick up a pencil, so no I would not call it luck, I just have about 24 years of experience doing it.
Writing is a skill that is taught in school, where as art tends to be less of a focus, in fact it is usually an optional course once you hit middle/junior high school. So I think a lot of us tend to have more experience/ basic writing skills. Which means that yes, artists usually have a baseline writing skill ( since it is a requirement in school) but writers may not necessarily have a baseline artistic skill.
There are a lot of artists who need a writer to either write or help develop their stories.
As many people have already stated you can develop your art skills as well, and in time draw your own comics!