Things They Should Study: how incompetent can you be and still successfully run a business?

This train of thought started with Bill Hendrickson on Big Love. He's an idiot, but he owns his own successful business.

Then I started thinking about real life, and it occurs to me that I've encountered more than one person who is an idiot and runs their business poorly, but their business continues to exist for years and years and years.

How can this be? Someone should study the incompetence tolerance of enterpreneurship.

Then this got me thinking that maybe I'm grossly overestimating how difficult it is to run a business. It all seems impenetrable to me, but if these idiots are doing it, maybe it isn't that hard? But then if it were THAT easy, wouldn't way more people run their own businesses instead of working for someone else? Think about how hard it is to find a decent job. If any old idiot could just start a business, wouldn't everyone just do that rather than running around sending their resume everywhere?