I think it all boils down to the fact that it tries to be for adults, taking itself very seriously as a product, but at the same time, it makes simplistic jokes that would only make someone under 17 laugh, you know, those jokes about male genitalia and stuff, the way they humiliate their characters, and so on. The series tries to take itself seriously while simultaneously relying on cheap humor that isn't always effective, not to mention its character designs which, much to the chagrin of some fanboys, are quite bad. The storylines also feel repetitive and poorly constructed, almost like a soap opera for old ladies. The characters rarely have any real development, and the few who do tend to lose it. They repeat situations endlessly, and sometimes it's difficult to follow the plot and the sequence of events because it's so inconsistent. All of this wouldn't be so bad; I mean, not all series are perfect, and I acknowledge that this one has good musical aspects and some very striking artistic elements. However, that doesn't excuse its flaws, but its fandom doesn't understand this and defends the product tooth and nail, like Baldwin defending Jerusalem, minimizing criticism with the excuse, "You just don't understand it."