While you're correct in observing that the first example is shorter and potentially easier to read at a glance, there is a method to the madness in the second.

While you're correct in observing that the first example is shorter and potentially easier to read at a glance, there is a method to the madness in the second. They inlined the CSS needed for content above the fold which speeds up load times theoretically. They then use JS to load the rest of the CSS later on so they can control exactly when the stylesheet is loaded...just linking like one would normally do would negate the perceived benefit. The end result should be comparable overall load times but the end user should perceive a slight decrease since important information is styled immediately. So yeah, the second is a little more confusing and in this case is drastic overkill, but their point still stands.