I find it funny that the ending of Empire gets so much praise and no one ever mentions Jedi's ending. Sure, there were ewoks, but you also have the redemption of Darth Vader, which, in my opinion, was done very well. Compared to Empire's ending, it is far more meaningful. Empire had a downer ending, yes, but what is the point of it? Jedi's ending was far more meaningful in comparison.
As for A New Hope/Star Wars, it's actually my favorite, as it felt like the best structured of the films. While it is very traditional, it makes good use of the traditions to create a logical, entertaining story, unlike Empire, which felt very muddy and unstructured to me. I suppose one of the major reasons it is disliked is not only that it meets general movie conventions, in terms of pacing, but that it is based on the archetypal "hero's journey", which many may see as cliche.