If you think of the length of the ending(s) in relation to the entire trilogy, and not just the third movie, it’s more than justified.

These movies are a work of art, made with such love and care that I just don’t see Hollywood reproducing anytime soon.

From the article…

What the film does elect to show us is, of course, long enough, and features several moments where Jackson could have made a bladder-friendlier fade to the credits.

Makes me wonder if the whole controversy just comes down to individuals bladder capacity.