Then I suggest you read the article as he gives a very good explanation.
Mozilla can only survive if a sizable percentage of end users perceive Firefox as the best browser for them, and this usually means that Firefox needs to provide the best user experience. Personally I think that other browsers currently provide a better user experience, and I see a lot of people around me switching from FF to Chrome. The reason for that is not Webkit , but Firefox's user interface.
In the end only the product matters.