In defense of CertainlyT
Zoe, Yasuo, Darius, and Thresh are probably CertainlyT's most complained about champions. For this, people actually have made several threads complaining about him; saying he's the "Worst developer" and so on. The only actual champion I've question his influence on was the Mordekaiser though I don't think it was CertainlyT's idea to make him a substitute adc bot lane. I'm guessing that order came from above and CertainlyT job was to make it a reality. CertainlyT also worked on one of leagues most widely embraced reworks: Warwick. To say he's the worst Dev is probably quite the opposite. He's not perfect but thats the essence of what makes him a good creator. His creations have all made heads turn in one way or another; either positively or negatively. He doesn't really make champions that are dull and uninteresting and for that, it probably makes him one of if not the best champion designers at Riot.
Back to Zoe and Yas however. These champions are truly high risk / high reward champions at the highest level. The reason so many people claim they are reward only is because most of the time they are being dominant at lower ranks where the players have limited knowledge on how how to beat them. It makes them seem far more dangerous than they really are. However, this is the exact same argument you can make for
and several other champions that are far more successful in lower elo than higher yet people take no issue with that fact. They are actually okay with needing the proper understanding and even team understanding on how to deal with them. When it comes to Yas/Zoe people want the champ deleted and their creator to no longer work on champions. This is textbook pitchfork&torch mob mentality. These champions can be beat and are more easily beaten by players with greater knowledge of the game.
I also take issue with the contradiction that these champions are dominating games and completely carrying to victory. Why's that an issue if there are several threads complaining that Riot is favoring more premade/team-based play? Shouldn't you be happy about Yasuo being able to carry an entire team by himself? Isn't that what you're actually arguing for? I'd think you'd want more champions like Yas, or Fizz or Zoe or Tryn or Nasus to carry a game to victory almost single handedly.
I think people dislike many of his champions because of the mobility factor. I think thats the crux of the matter tbh. There is a huge portion of LoL who cannot stand fast moving objects/enemies. They emphasize "strategic" game play which I find to be included in that contradiction stated above (are you in favor of heavy team strategy or not?). They present this idea that Yasuo and Zoe and others are outside the realm of strategy with their LC$BIGPLAY$ and are more focused on fast-paced action outplays and flashy stuff. I think these champions lend a balance to team play and not destroy team play. They are also pretty fun to play as which is fairly important.
There are a few more things I could say but I think I'll leave it at that for now.

why the hell people are complaining i don't get it
gets reworked and ruined for being "frustrating"? lul