I guess higher-elo player suffer of a sort of divinity complex if you have to put yourself on higher level so aggresively.
Let me say that I'm a pretty decent Yasuo player myself (decent, not pro) and I recognise that he is a strong character expecially with a team that can give him good knockups. But there it ends, it's a strong champion, not over the top. There is plenty of other strong champions but you don't see the whole boards whining about them (Azir is a strong champion for example and seems on the same pick/ban ratio).
My opinion concerning Yasuo hate is that it's really not clear what to do because he has a good variance of tools but none of them is gamebreaking because there is a counter for any and each of his tricks. Said that, if you stack up against a malphite+yasuo team your team is at fault. Good sinergy in a team means that enemies must work together too to nullify it, each time ppl bring the team factor sustaining that Yasuo is OP they don't consider that they themselves have a team and counterpicks exists.
Now I'm sure I haven't covered 100% of the situations etc but trust me that Yasuo is beatable if the skill level is the same or yours is higher. And that's all that matters.