I think the heavy reliance on these templates is a good clue. Apple TV's interaction model is a lot about swiping around from tappable element to tappable eleme

I think the heavy reliance on these templates is a good clue. Apple TV's interaction model is a lot about swiping around from tappable element to tappable element. Arbitrary layouts will make this a miserable experience. Apple probably wants to establish a number of layout patterns that they believe will yield a good experience.