I'm not opposed to nerfing champions who are considered strong/overbearing, but winrate does play a large role in that as well and we have to be fair.
Someone like
who has such a high skill ceiling (he does have a high skill ceiling due to popular belief, although I'm probably going to be downvoted just for saying that) has never had a high winrate for longer than a patch or two at a time. He's got a massive playerbase — one of the largest in the game — and yet has consistently hovered around a 47-50% winrate across all ELOs. Higher ELO players can capitalize on his weaknesses more which is why you see him at low ELOs and why he's scarcely seen at others.
Most of the champions complained about just aren't a problem at higher ELOs because the players know how to read guides and/or adapt to the champion's playstyle. Pyke, Yasuo, Irelia, Akali, and everyone else do have their counters and can be beaten in lane. In fact, I wrote this comment right here detailing the many ways Pyke can be beaten in lane, and that didn't even cover champion counters for supports and ADCs.
IMHO - People don't make an effort to change their strategies enough to actually counter the things they dislike fighting. One strategy will not work across a multitude of different situations. I do agree that more counterplay should be given to certain champions, but hitting them with a straight nerf isn't right because it won't fix the problem at hand.