Impulse has been a staple skill for Magika DPS users for a long period of time.
Everything that follows from this false assumption should be questioned. The skill was failing at its premise, to be a useful source of magic aoe damage. Lightning heavy attack did it better, from range. Putting your dots down and staying out of melee range kept you safer without losing much damage on a lot of builds, it just wasn't worth casting in my (PvE) experience. It's true that it takes high CP for the stacking rules on Lightning Heavy to start scaling it to something worth using. So maybe below 250cp, Ele Ring had a use case? I'm not sure.
They changed it to something else, something different enough from other abilities to have some utility. It seems like a cool idea to me. If nobody uses it after the update, maybe they'll try again this summer.