Why would you not nerf Yasuo?

(I am in bronze IV if you don't think my opinion counts, cool story) I have tried to play against a yasuo many times in my league experience, but I have to say I hate yasuo. I am okay with all other unbalanced champions like darius and Irelia, but I hate yasuo. I have had to deal with teams build around a yasuo wombo combo(alistar supp, kalista adc, malphite top). I have also been trying to get better at mid lane which is extremely hard against a champion with no mana, low cooldowns, and two ways to stop abilities and poke, so attempting to try to get better while against him is horrible. I wanted to main anivia but even with me building 200+ armor I got stuck at a point when he had so much armor pen he felt like he was doing true damage. He also can sustain easily just using his q's. His windwall size increasing is what really annoyed me. He could easily put it up and 0 abilities could be casted by my team while they could use theirs. His passive can make him too strong past 15 minutes. Another thing is that people will just say to counter pick him, but its not healthy balance to just make a counter that if you don't pick you lose the game. It removes the freedom to play champions that people want to play. I know riot does a very good job nerfing certain champions, but it feels like they have a tendency to just help some champions more than others. You can see this with the Irelia "nerf" where they just increased the cooldown. I don't think they are willing to nerf him because so many people play him. I understand when balancing someone you can't completely change their concepts and abilities too much. Except for Ryze of course. I think that Riot just missed how op early game crit chance champs have gotten, I hope when they think he needs a nerf they just don't nerf his items because that's not his problem. This may just be me ranting while being tilted, but I would love to hear your thoughts.