I understand that Mozilla changed focus in 2013, but the problems started before then. According to all of the browser usage share data I've seen, Firefox's sh

I understand that Mozilla changed focus in 2013, but the problems started before then. According to all of the browser usage share data I've seen, Firefox's share began to decline around the end of 2010 or the beginning of 2011, about two years before Mozilla shifted focus to Firefox OS. So, what went wrong between 2011 and 2013, when Mozilla was still focused on the Firefox product but its market share declined from more than 30% of the market to less than 20%? That's what really went wrong. The change of focus made a bad situation worse.