To try and answer your hypothetical scenario, or at least what I think it is you're pitching here: I have yet to see someone attempt to run an Iwaku Mythos RP and receive no interest. Most of the time, the amount of interest is massive, and at times more than the GM could possibly handle. The Vault War has something like 60 players. When Rory ran Iwaku: Azazel and Iwakutsuki, he had to have co-GMs assist him in approving character sheets and playing important roles, because otherwise the amount of players would have been unmanageable. If someone were to start a Mythos RP and no one joined, they would have to be making some kind of egregious error.
That said... I have to agree with Grumpy. GMing your own Mythos RP is not a light undertaking. It's not so much the history itself, as any of the Mythos can be revised and re-imagined to your heart's content; it's the years of precedent, the high expectations, and the sheer competency level required for managing a high-numbers, high-power player base in the type of premise that often brings out the worst in roleplayers along with the best. And beyond that, there's no soul in it when it's run by someone who doesn't have a connection to the community and the people here. It's not a matter of elitism; it's more like if you were trying to run a fanbased roleplay that's based on a book you've never read and don't care for. You have no personal connection to the material, and it will not have the same appeal and cohesiveness for your players that it would when run by a fan.
My advice? If you want to get involved in the Mythos, start as a player and work your way up.