It's not so much that everyone needed an explanation, just that the whole thing was poorly-paced and abrupt with a few glaring plotholes or just dumb crap. And it's always nice to see a better denouement rather than a vague, suggestive one. It was the end of a trilogy, not a two-hour film. Not one for analogies but no one would've liked LOTR to end with the ring falling into the lava, followed by a clip of eagles flying to Mount Doom, Aragon wearing a crown and Gandalf getting on a ship (although that film could've done with a few less endings...)
Plus, I think the more important bit was fleshing out the starkid nonsense and it helped assert the themes and ideas a lot more clearly.