That totally explained it. By the end of Bionicle, I felt like something was missing, but couldn't really figure it out. You totally hit the nail on the head, though. Like, with a sledgehammer.
Bionicle was so interesting because it was brimful of heroes with mysterious powers and unknown pasts, and a dark and sinister being who could cause so much damage from his little hiding place, and a big tropical island with every climate imaginable, and armies of bug-like creatures that poured from the depths of the earth.
I suppose as some things got explained or ignored (sort of like LOST XD), it partly satisfied fans, but at the same time took away a lot of what originally attracted them. Makuta lost so much of his evil, omnipresent feeling when he had a name and a race, and when him being Mata Nui's brother was brushed aside as, "Oh, he was just being figurative and delusional."
Plus, the characters we originally started with were left behind, then brought back, then left behind, until there were so many characters in so many different universes that, by 2009, (speaking only for myself here) I was having a hard time keeping track of who was evil and if they even were evil and what they looked like and whether they had appeared previously in the storyline. I never did properly learn the names of those Glatorian... sorry, Glatorian...
So the point of all this is to give you a huge wall of text explaining how you're right. XP
Turakii