User blog comment:SirAston/Theorycrafting: Ohmwrecker/@comment-5266525-20130913142224

""While Ohmwrecker was originally designed for tanks, the tank role has a lot of other tools that effectively divert turret damage. These changes reposition the item as an aggressive option for supports and casters.""

- 3.02 patch notes

Ohmwrecker really just has a problem with the current metagame, alongside a select few other items like. It's meant to help break stalemates when both teams just spend all their time camping under towers and not making any attempt at offense, but obviously that doesn't happen these days.