had no idea about that. this actually change all I thought about the gameFun fact about that, and something a lot of people don't realize:
Cloud bases all of his "heroics", including using the Buster Sword, off of what he knew about Zack.
Cloud is actually a massive wannabe loser that lost his memories after trying to save Zach. Cloud went brain-dead, lost all of his memories, and assumed Zach's identity after Zach told vegetable Cloud his entire life story. Before losing his memories, he was a generic guard that lied to his family and friends about having grandeur of joining the SOLDIER program, but the fact was that he just wasn't good enough to be considered. He just happened to be at the right place and the right time to save Zach, which led to the events of Cloud being subjected to Jenova cells (making him brain dead, because he's a loser).
Zack wielded a giant sword, because it was gifted down to him from his mentor, right before dying by Zack's hand. Zack killed his mentor because the mentor was going crazy from the SOLDIER program and Jenova cells (which is what happened to Sephiroth).
The mentor carried around the giant sword, not because he actually used it (he actually fought things with his fists), but because his parents were really supportive of his military lifestyle, and bought him the biggest, baddest sword they could afford. He carried it around for sentimental reasons, and only ever used it when he got serious. He did end up using it against Zack before getting killed.
But before that point, Zack would wield a pretty boring sword, not even long enough to warrant using it with two hands.
So...yeah. The big sword is intentionally ridiculous, and people have just been dragging it around for sentimental reasons. Cloud only ever uses it because he's batsh** and doesn't really know any better. Zack used it, so now he does, and...that's all there is.
Cloud has an attachment to Aerith because Aerith and Zack used to date. With the events that happened with Zack being so fresh, and forgetting about his past life, Cloud doesn't really remember much of Tifa, which is partially why there's a major disconnect between them at the start of the game.
As the game progresses, Cloud starts to get his original memories back, including of Tifa, which is why things get better between them (well, that, and the fact that Tifa basically nurses him back from being brain dead [again]).
Convoluted as plots go, it's still miles better than the Final Fantasy XIII (and all of its entries') plotline. At least the FFVII series didn't go "Welp, the world is ending and you're an Angel now".