Why is AP so Overpowered

Seriously! AP Casters do damage? That is so op. I think that all AP Items should be removed from the game, along with every single champ that has an AP scale. Every single ability that does AP damage should have a hidden passive of starting a surrender vote. Rito, balance your game, and please buff . His nerfs in Season 6 make him completely useless. I went 0/41 against a in lane (who should be nerfed by the way), even though the guy was only Bronze IV and I deserved chalenjour. My team was also trolling.