I think your premise, "that we can't all be creative freaks... but we can all work really really hard" is not actually true. Dig up the biographies of any of the people you listed and you'll find that they devoted enormous amounts of time an energy into their work. Tell me that you could really pull 10-14 hour days doing one single thing? And not just 10-14 hour days of 'work' but true practice, which pushes you further. Additionally find me a single case of someone with "natural creative" talent who achieved any sort of success without the requisite amount of hours put in.

I personally find the "natural creative" to be a myth that people prefer to persist, it means that if I'm not Van Gogh, I can more easily say "well I just don't have the talent" and give up right away, and if I'm a bright college student I can just get pissed at the world for not recognizing my "genius" rather than just work at something all day.

In short: extreme amounts of hard work and dedication are more rare than cases of natural talent.