This is one circlejerk I cannot argue. I am sorry if anybody expected me to. But at least Riven gets shut down when she is shut down, and isn't useful again unless the game hits 6 items so leads don't matter. Yasuo can go 0/6/1 and still be monstrously strong just by farming a short while. Don't get me wrong, he can be dealt with really easily by skilled players, the problem is even if I learn to beat him I cannot assure that my top laner/mid laner will learn to beat him. This may apply to all champions to some extent, but I cannot think of many if any who become a monster like Yasuo does regardless of how ahead/behind he is.
Overall it isn't even about winning/losing to him, it is that he makes the entire game of League about him when he is in the game. He is good at split pushing, good at laning, good at skirmishes and as long as his team has some displacement good at team fights as well. If he fails in one area he will just succeed in others making him a permanent threat. Which would be fine if every other champion in the game was like that, but very few are.
A shut down Riven is near worthless, still usable but even if she cuts neutral she is just another player in the game. She only takes over the game if both fed and played well.
A shut down Darius can still be frustrating but can be focused down quite easily, kited and lose his worth. If cutting even he does command a lot of fear but can still be played around.
A shut down Jinx can add a little DPS and hope to farm up for later usefulness, but overall is just an easily popped squishy and even when cutting even is just an ADC.
Any champion can take command of a game if they are fed and/or play well. But Yasuo, similarly Vayne as well, are the only two champions I can think of whom even when completely shut down I think about and fear their influence over the game more than even the fed enemies on their team. Because they feel like no matter what they will become the most important thing in the game by the time they complete an item or two.
I wish I could defend Yasuo, he is really attractive and a cool champion. But honestly I cannot. Sorry if this upsets anybody.