Even Rioters are saying it: Banning Yasuo is literally wasting a ban *if you're not bad*
"Yasuo already struggles with being a viable champion the higher you climb, and instead has a lot of his playrate derived from players who devote themselves to mastering him (and even then aren’t rewarded with the typical winrate growth you would expect)."
http://www.surrenderat20.net/2017/06/red-post-collection-june-15th-mid-patch.html
So the question is: Why are people in ranked banning Yasuo? If you honestly believe in your skills, you should ban real threats.