For the same reason why some folks must be kept away from reading medicine even if they qualify on the scholastic level, because they lack the emotive and analytic abilities to comprehend that there are shades of colors and not everything is in black or white. This goes for political studies too.
I went through the exchange again and I believe the misunderstanding lies in the interpretation of the world "leader".
I was using the term to describe someone with outstanding leadership qualities.
Those that were opposing my views took the word "leader" to be synonymous with "Prime Minister" or "President" or "CEO".
Very few of those who hold high office are actually leaders. Many of them are anything but. Pinky Loong is one such example. He doesn't have an ounce of leadership in him. If he wasn't for his father, he wouldn't even be a department head in medium sized company.
The real leaders are few and far between.. Margaret Thatcher, Mandela, Bill Gates, Steve Jobs come to mind. None of their successors had or have what it takes. Microsoft is now being run by a clown and Apple by a technocrat. The future is not bright for these companies.