The title was pretty clear so here goes my theory. I have been thinking since the three log poses nami got to navigate in the new world, it's very unlikely that to every island in the new world there are three new ones to go to, that would be just a shitload of islands, so it's possible that depending on the pose you choose to follow your ship might not be moving foward but sideways or even backwords. So taking in consideration that Roger said to whitebeard that there is indeed a secret to get to Laftel, and that Luffy has what it takes to get there, I came to a conclusion to what that secret might be. What if to get to laftel you have to choose the most dangerous island all the way there, that would mean that 95% of the pirates wouldn't be going on the right way at all, and the 5% that were wouldn't have the strenght to get there anyways. If you add that to the Yonkou conflicts and the Marine assholes, you got that only the real pirate king can get there.
So...I thought that was pretty got, but I'm sure the theory got it's flaws, so feel free to criticize. Marijuanna out