Just to pick on one of those supposed great scenes, Order 66 is terrible. The jedi are portrayed as clueless buffoons throughout the PT but at no point is it worse than that scene.
Not to mention the over the top emotional music when why should we really care about any of those people? Most of ROTS is pretty much bullshit when you get down to it.
Obviously a movie should be able to stand on it’s own, and when looking at Order 66 purely through the lens of the movie, I would agree, but the outside-of-movie material helps to alleviate this problem.