Hmm. Let's talk about this before we get into too much "thread drift."
There are people who are born with superior natural abilities in certain areas. For those people, performing tasks or thinking; reasoning or high-level stuff is just easier. If we go with that theory, then we can believe that "natural talent" is simply a product of genes. But it's not.
You have to have that genetic makeup AND have had a nurturing, supportive environment to grow that talent within before it becomes truly "natural." Writing, especially. No one knows their language or how to write things when they are born. There's nothing natural about that. Both are a learned skill. Some will leanrn them faster than others. Some will grow them faster than others. Genes and environment.
To be more clear, by "nuturing and supportive," I don't mean having a mother or father figure to hold your hand; or someone to tell you it's going to be OK when you skin your knee. It is some of that. However, really, "nuture and support" is more about access to money, resources and time to exercise what is genetically latent. And there are NO overnight success stories, period.
That said, all that is about 15-20 percent.
Another 40 percent percent is coaching, planning, and discipline. Excuse the analogy, but even John Holmes/Peter North/Jenna Jameson had to have a forum in which to exercise their given, umm, talents and natural gifts. As a more social comparison, Michael Jordan lost big for his first few years as a Chicago Bull. Other athletes have as well. More directly in context, how many brilliant recognized writers ate Top Ramen and mac-n-cheese until they "made it big?" Almost all of them, save the Norman Mailers of the world. So, there is something to be said for honing talent, being in the right place to exercise the talent and exercising it in that fashion over and over again.
Finally, the final 40 percent has nothing to do with either. It's about relationships and who you know. Don't believe me? Go publish yourself and see how many copies render themselves to readers without marketing or help from people who market/distribute. There's a huge chain of custody on that "raw talent" and honing of skills that starts with you but ends with the reader. And in between, there may be as many as 100-200 people who bring your book, poem or other tome to live.
Similarly, to use a military analogy, a pilot flies the jet fighter. However, there are a dozen mechanics who ensure it gets off the ground. There are cooks who feed the pilot. There are personnel people who process paperwork for the pilot to ensure he can go fly ontime and without hassle. There are doctors and nurses who keep the pilot healthy. The pilot can't drop bombs unless someone pulls them out of the bunker and loads them. You get the idea. The flight doesn't take place without the work of at least 200 to 300 people to get him in the air.
Dismiss any of these and you'll be missing the big picture -- it's balance of all these things that makes any vocation or venture a success.