Why does no one buy Ohmwrecker

I buy it as core on my Nasus build unless i get super behind in which case i buy The tank stats are great against AD top laners the Hp regen is great sustain the CDR works perfectly and the amazing ms passive is really underrated for one i dont have to tp back to lane cause i get back so fast so i can get in free backs without losing pressure and the diving potential once i scale up is incredible they are forced to deal with me giving my team lots of time to do what ever they want as they have to send 3 people to handle me i feel like this item would work well with other top laners too but i wonder why no one every gets it