The problem with Yasuo is that he completely owns the lane.
Everything that happens in the lane is completely in his control. He can clear waves extremely fast with his E + Q for no cost (resourceless), but can freeze just as easily. He can get to almost any location in the lane nearly instantly because of his dash that has basically no cooldown, if you're not under your tower or in the side bush then regardless of where you are you're basically in melee range as far as Yasuo is concerned. He automatically wins short trades with his passive shield + windwall, and wins long trades with his short cooldowns and sustained damage. It's extremely hard to poke him since he's zooming around left and right constantly, and even if you do manage to hit him his passive shield will negate all the damage, and it recharges very quickly. Once he gets his ult you can't be aggressive in lane, you have to sit like a little bitch under your tower because if you get anywhere near your minions then he's just going to dash up into your face, ult you, and then crit you a few hundred thousand times. His abilities have extremely short cooldowns, so he can spam all of his abilities as much as he wants and you can't exploit that because he's resourceless and his abilities are always up.
The part that bothers me most is that for the overwhelming majority of matchups, if you ever kill Yasuo in lane, it's because he fucked up, not because you outplayed him.
(definition of fuck you yasuo)

in game = all champion in URF game.