You would have to ask someone at Mozilla, but his handling of the situation got very poor results. They didn't anticipate it, didn't have a plan (AFIACT), and didn't manage it well once the crisis began.

It hurt Mozilla's image and created a distraction from Mozilla's mission among employees and the public. Everyone is discussing Eich and politics; few are discussing FirefoxOS and other initiatives.

Part of the CEO's job is to manage all that.