Why do founders sometimes ruin their companies?

This article from the USA Today describes eight companies "ruined by their founders". It states, "Perhaps the greatest hallmark of founders who ruin their companies is that they appear to look out mostly for No. 1 rather than the interests of the company and its shareholders. For starters, they accept excessive compensation". It also describes the compensation and ownership shares. Students might try to answers why the ownership rights are insufficient to prevent ruin.