I'm curious why the top is preferred over the bottom:

Open elements on the same line.

The 80-character line limit is a bit tight, so we opt to conserve the extra 4.

Yes:

  return <div>
    ...
  </div>;

No:

  // "div" is not on the same line as "return"
  return ( 
    <div>
      ...
    </div>
  );

The latter I feel is much more readable and clear than the former, as it has a certain symmetry and cohesion that you find in normal html. The top one seems to be break readability. Wondering if anyone can comment on this specific decision?