Thanks for your perspective.

> it was just a lot of hard work

If that was true, then many would have done it instead of only one.

> Their was organization before Inca, as there were tribes which were organized. The Inca just took them over and re-organized.

Organizing a small scale is commonplace; everyone does it. It's the large scale that only the Inca managed.

> The Inca were also geniuses.

Must have been! But in what way? And it can't just be one person; you need a whole culture (especially with limited communication, the Inca depedended on locals everywhere understanding the concepts, methods, etc.) - what was special about that culture? Where did it come from?