I think you guys are overreacting to this suggestion. Who knows why, maybe cause the idea that people could get supreme robe with E.T while you had to do runs pisses you off.
But seriously, getting 30-40 E.T is way longer than farming the cape in TM Abba/SoT, and the robe is account bind so no people would be able to buy it from other players. I don't see why you make so much fuss about it.
Though, in my opinion, I think it's rather useless to implement that option because most of the people would prefer to do the runs instead of farming 30-40 E.T