He didn't say content, he said features. Those are all features of FireFox that IE doesn't have. Content is on the web, that's going to be the same for all browsers.
Content is what sells, not user features. Remember, the browser is free. If you think the content is the same in all browsers you really don't understand what you are talking about. That simple is not true. Content looks different in different browsers. JavaScript works differently in different browser (FireFox has some JavaScript problems).