Square Enix really have no faith in their product, thats for sure. They could have just made Noxious a self buff if upholding it on multiple enemies was truly that difficult. This change however removes a bit of gameplay of the class that played part in making it more engaging, the decision making of when to use Steel and when to use Dread fangs.

Typical knee jerk change. Remove friction and uniqueness, push class into the mold of all other classes. Every class needs to play the same, all day, every day.