If you want to excise any and all nuance from her story, sure.
Fate may have created an irredeemable monster of Yotsuyu and certainly denied her the strength to be a better person, but I can still empathise with a rabid dog while putting it down.
Yotsuyu's is a tragic tale of someone who was beyond saving.

I also don't think it's fair to compare Fordola's vengeful anger and determination to Yotsuyu's all-consuming hatred.
The two stories start differently, unfold in different ways, and will inevitably end in differing ways.