"This champions winrate is 1 - 5% higher than 50%"

I can answer your question, the insert champs you put there are whined about alot, and the reason why nothing is done about the ignore champ section is because the first 2 are fan favorites so they are off the table and the other 3 aren't played that much

55% is pretty busted, assuming you have a good sample size. The only champion right now with a 55%+ winrate in a role also has a 0.6% pick rate.

Since when do people NOT bitch about Yasuo 24/7?

As a J4 top main (started early S5) - he's only really become super strong the last 3 patches or so. It has also coincided with the end of the season. There's no reason for Riot to nerf such an underplayed champion in an off role when his original role (jg) isn't getting out of line.

J4 top works well because of the top lane meta right now. He also is a champion that is generically useful to a large variety of team comps while being relatively easy to play (i.e. he should probably sit above a 50% win rate). That all said, he's been #1 for 2-3 patches now and will probably see nerfs if he isn't hurt by the preseason changes. Riot tends to be a little more careful about stuff around preseason because an unnecessary nerf can compound with meta changes to make a champion really weak.

As for the others: Yasuo gets whined about like mad... Thresh gets whined about and then people accuse the whiners of being low elo can't handle him. Never understood that as he was a staple pro pick for ages, but w/e. Alistar doesn't get whined about but like J4 he offers something that greatly benefits a large variety of team comps while being relatively easy to play. I ban Sion and have wanted him to see nerfs for about 14 patches now. Players just don't see the OP-ness for some reason. I won't bother trying to defend that guy.

p.s. not fair that the champ icon selection list has a greyed out ahri icon when aatrox is the first in the list