Yasuo is a champion with clear and rewarding moments of strength both defensively and offensively. His visuals are easy to read, his intentions are telegraphed, his strengths are condition, and he encourages - nay, forces - both players in the lane to engage one another during the laning phase.
As a result he is a well designed and, contrary to the massive amount of bitching, healthy champion. I'd argue he's the pinnacle of Riot's stated design goals of 'moments of power' and 'laner interaction'.
With that out of the way, Yasuo threads are great for a few things:
'#1: Outlining how blatantly Board's users misunderstand the buzzwords they use.
Toxic, hypercarry/ (interchanged a lot, though technically different things), anti-fun, stat check, free stats, no counterplay. These are all terms which Riot has created throughout the years to help explain abstract design principles. Of these terms, the only one which could possibly apply to Yasuo in his current form are free stats (his crit % increase, which makes perfect sense when looking at his kit as a whole). The other ones are demonstrably untrue.
'#2: showing that Boards reacts strongly to visual clarity.
It doesn't take a keen eye to pick through the threads here and see that champions who have clear and visible power are reviled, while those who are just as dangerous / more dangerous in the same way, but don't have massive warning on that danger, fly under the radar.
This point, ironically, is very much 'proof is in the pudding' when it comes to Yasuo being well designed.
'#3: Understanding Boards players don't want to understand champion interaction.
Simply put, League is fast approaching 150 champions, and all of those champions are supposed to have strengths and weaknesses. For some champs, their strength is being decent at everything but excellent at nothing. Others specialize in a handful of areas; Nocturne has unrivaled target access but lacks the burst, or tankiness, to be a super strong diver / assassin in most cases, Renekton has a monstrous lane phase but doesn't scale, Darius storms through team fights but is super vulnerable to CC / kiting / being focus fired.
Due to how those strengths and weaknesses interact, some specific champs will make very hard MU's for other specific champs. Such that if the person playing the exploited champ is unwilling to adjust their various factors, they are going to have a rough time.
This is fine. This is normal. This is not a problem.
This is a huge problem in NA in general. People need to get their head out of their asses and recognizes that champions and roles are supposed to have strengths, and if you fail to give those strengths respect you are liable to get shit on. The answer is to improve as a player, not scream and wail for nerfs like an autistic baboon.