Each champion has their own skill flooring and skill ceiling, each with their own strengths and weaknesses. I am a mage player, so stuff like this is more in the abilities. Annie may have an instant stun but her range is pathetic; Syndra may be good at bursting but she is immobile. It more has to deal with why play a harder and more rewarding champion when you can play a simple one with no draw backs-- say Ezreal and MF. Both have good AD Q ratios. Who would you chose: a champion whose Q is first it, has two other abilities that deal damage and kiting, and an ult with a delay you need to predict where your opponents are going to go OR a champion with a point and click Q, two utility spells, and an instant cone aoe ult?
From my perspective, as playing as the second strongest bursting class, mages, I have always hated it when a stupid crit deals over 1/3 of my health. An auto did that damage, a basic thing in the game, where my abilities deal less than that and can be avoided or missed.
I hated this the most when Lethality came out and non AD assassins abused this stat. I never understood why armour pen needed to be touched, especially seeing how AP is the same: one percent magic item and two flat. Why make it where AD is so much better over AP? This season made it where I really just couldn't enjoy the game like I used to. I avoided mid because hate the fact I can screw up an ability and miss out on a ton of damage yet an auto attack deals so much.
MF's Q with lethality items is so... egh. Even Rengar wishes he had that burst in ONE ability.
Again, this is my opinion but I wish someone could start a movement where they stat this damage distribution issue RIOT has going on. I would gladly support it if done well to the best of my abilities.