Wouldn't really work either, would only obstruct runs. Think about it. Trying to stun ifrit? You can't, the thunder of a blm just did that and now its immune. Actively using it would be darn hard as well due to cast times. Ice does snare you. At least freeze and Blizz II do. But again, takes a long cast time, or you need to get closer to the mobs, which might end in your death since BLM is squishy.