The OP image is missing some additional effects on the weapons as well as context. As I recall, Curtana was the only sword with +HP on it, restored MP on attacking sometimes, and increased the damage of Spirits Within. Bravura reduced the cooldown on Vengeance (I think), Gae Bolg increased Jump damage, etc.

You don't have to have unique stats to have a unique item. They could throw like 500 spell speed on a paladin or dark knight sword, for example, if they wanted to enhance flash/clemency/unleash. They could put a ton of INT on a healer weapon to let them use some nukes outside of Cleric Stance. Unfortunately, we have so few relevant stats for each class that making a unique item with them is very hard. I think regardless of whether they're unique or not, we do need more stats with more effects. Right now gear is a complete snoozefest.