An Ability Power AD Carry?

Ok, so I'm curious, why hasn't Rito released an Ability Power champion that focuses on AA's? I know it's a weird concept, but literally every other single role can help shore up weaknesses on the team by picking an AP or Ad champ except the AD Carry. It wouldn't be too difficult, make the E a passive that makes your AA's scale off of AP instead of AD. The ratio could be something like 75% (made up value, I'm not a developer) of your total AP. I don't know I just think it would be an interesting idea and help the ADC contribute to their team. i can't tell you the amount of games I've been in were everyone picks an AD champ and I wish there was an ADC that was actually AP. I know people will mention Ziggs, but he's not quite what I had in mind :)