People like Musk, Jobs, Edison and others are valuable because they see future possibilities - not pipe dreams but real possibilities - and turn their attention towards realising those goals by putting together teams of people who stand a chance to get there. Some of them - Musk and Edison in this list - do some of the work themselves, others - Jobs - are more 'visionary leaders' who somehow manage to inspire or scare others towards achieving the goal. Once the company is up and running these types of leaders tend to look elsewhere to break new ground because the day-to-day grind of running those companies is not their thing.
Mozilla does not need to find future possibilities, it got its goals handed to it by Marc Andreessen via Netscape: create and maintain a browser. The task of a non-profit CEO is to make sure the company remains funded. This takes a different type of person, someone who has or manages to create contacts within places where money is to be found. The last series of Mozilla CEOs saw this differently, these women convinced themselves that they were there to 'change the world' by means of pushing ideologically loaded programs and propaganda onto it. They considered the true reason for being of their organisation - create and maintain a browser which competes against the duopoly by giving control back to the user - no more than a means to get the funding for their ideological crusade. They also increased their own piece of the pie markedly in the process in some strange realisation of Orwell's All animals are equal but some animals are more equal than the others quote.
