Pardon me throwing my two cents in, I love discussing alternate timelines and alternate universes.
Actually there would be a timeline where the great beings did decide to put romantic love into the Bionicle. But this wouldn't come about because it is a logical choice. It would come about because of the main timeline. This rather baffling timeline would come into existence because the main timeline exists. Each action has an equal and opposite reaction (yes, I am fully aware this is basically Newton's third law). Many timelines in various franchises work like this whether the creator/author realizes it or not. See any story that has a gender bend or opposite alignments timeline. And it is safe to say that real life alternate timelines would most likely work like this. You would have timelines form based on action and inaction.
But to be fair, given how contrarian the romantic love timeline would be, it is safe to say that it would be hard to find this timeline in the vastness of the multiverse. It would be hard to locate on top being very far out into infinity. So it is safe to say that this timeline would never interact with the main timeline given how out of character it would be for the great beings. On top of that, it would potentially be one of a kind. Basically it is so obscure in the multiverse that it might as well not exist.
Insert something about different headcanons here, lol.
Again, pardon my intrusion. I tend to nerd out about alternet universes and different timelines. It is a very fascinating aspect of both science fiction and theoretical science for me