Why are there no Armour Aura's in this game?

As a support, I just want to know why there is no Armour Auras in the game. Supports get to choose and , that BOTH give MR resistance to all members. But there is no Armour equivalent? I recently played SMITE and they have both an AP and an Armour Aura option. I do not think it would be "game-breaking" to add one that gives an armour buff to all champions around the support. I would buy it just for that, without any additional effects.

It seems to be a consistent theme with Riot in removing Armour options for AP based champions. Armour got nerfed on , currently the ONLY Armour/AP item, bar which is a supportive item. AP also got taken off , which used to be a great option on a lot of mages. (Basically got removed instead of doing the obvious thing and changing ).

So does Riot feel that armour/AP options are not important, especially during this season which has been mostly dominated by AD champions and the "marksman" rework which gave many ADC's added power? Especially since AD's get which doesn't lower their damage hardly at all and gives them huge MR benefits and shield.