The current political system selects our leaders and decision makers through a process of nominations and elections. However, I suspect the main trait that is used for selection is "Sales Ability" - the skills to influence people. Maybe the sales skill is least useful for analysis and decision making (but not leadership)? The point is that the system is prejudiced against people who may have developed other skills at the expense of their sales ability.
Clearly there are some remarkably capable politicians and I don't wish this question to disparage them or indeed insult sales people (I'm married to one of the best).