Just curious who thought it was smart.

so your excuse as to why is because its also a great escape tool? That's a good reason to give it the damage to one shot anyone who doesn't conform to tank meta.

A slightly smaller area doesn't mean much since he can just use it to survive the fight also which forces you to run and get destroyed by his slows and damage or you fight and get destroyed by his one shot ult that heals him more then any single target heal, Mana isn't the problem, and his passive getting nerfed doesn't fix the fact his ult one shots carries.