Lets name all the champions who WERE nerfed when they became popular despite not getting any changes

I'm going to get started, I'm sure their is more, but I'll try to add them as they are suggested -

1. Twitch - After literally nothing but slight nerfs and a graphical rework since august of 2012, he was absolutely gutted in patch 4.10 when he began to appear in about 10% of games (and an average win rate), and hasn't been seen since!

2. Viktor - Suddenly started seeing some play (~10% play rate) with around a 50% win rate - Nerfed pretty hard in 5.16, still seeing some play rate

3. Sejuani (suggestion) - Okay, this one technically qualifies, but it's entirely due to cinderhulk. Then again, Vayne's all because of BorK, so meh.

Meanwhile, Vayne's been the most played ADC by far since at least 5.10 (~35%), and's rocking a very solid win rate of 52%.

As an honorable mention, Ahri pretty much always has one of the highest win rate AND play rates, but that's not due to them forgetting about her or blaming the meta, that's because she gets buffed anytime she isn't the most dominate mid laner (and sorta nerfed sometimes when the QQ gets loud enough) - you can pretty much count on her always being played in 15 to 25% of games, and a 52-54% win rate in almost any patch.

What makes these champion's less problematic then Ahri or Vayne?

And why are the meta and similar arguments fine for Vayne, but ignored for everyone else?

Can we get some explanations about Riot's lack of consistency and/or favoritism.