User blog comment:ClariS/Why Not Buff Instead of Nerf?/@comment-3974211-20120901111850

While it's true, the opposite is also true.

Last year, Kog'Maw, Graves, Caitlyn and someone else whose name escapes me (Vayne?) were nerfed. Now, Corki, Ezreal and Graves have been nerfed (again, in Graves' case). Now is it Tristana, Miss Fortune, Varus and Draven's turn? And then next year we'll see them nerfed, and then Kog'Maw and Caitlyn will be the strongest against by default. Urgot, Twisted Fate, Sivir and Teemo remain mostly unseen, although Urgot goes through phases.

Or, you'll get to the point where AD carries are just weak and you get casters playing bot... or, even, casters assuming the role of AD (Malzahar, Annie, Zilean, etc). And why not? The base damage on casters is high enough to be useful early game, and late-game carries are all about right-click... Annie and Zilean both out-range most AD carries, and Malzahar gets free crits with his minion.