I believe the criticism regarding the huge materia plot is that it's mainly just padding. You go to all this trouble to collect the huge materia and what do you do with it? You keep it locked up in Bugenhagen's planetarium. You can't even get any useful materia out of it unless you have fulfilled certain objectives.

In short; huge materia is a cool set of side quests that has been inexplicably dragged into the main quest. So I find it hard to disagree with that one, plot-wise it's completely unimportant.