Most creative minds don't want to be precise at many things because it ties them down. They prefer the chaos, as it feeds them. To learn more about this, look into Carl Jung which are elaborated with Myers & Briggs's Judging/Perceiving preferences.

But there's more here. Most great minds were not about being a vassel of knowledge but being creative with that knowledge. Smart for its own sake is worthless. And so I think you're picking up on the common thread of creativity in great minds, and its ambient indicators such as poor spelling and being messy, etc.