When Riot announced the Rengar rework, somebody (MM actually) asked if Rengar was going to stay as an assassin. A Rioter responded with a snarky comment. Basically, he said, "It's a part of the assassin rework, so of course he's going to be an assassin." Several months later and Riot has officially classified Rengar as a diver, and said in an interview that they are happy with Rengar's state as a diver, that it was part of their goal, and that if he stays stable, he is unlikely to receive any changes. If you guys wanted to make him a diver, then why the fuck would you say that he was going to be an assassin? Also why is a champion with a 46% winrate considered fine? If this were Lee Sin, you guys would be shitting your pants. But that's only the tip of the iceberg.
On the Rengarmains subreddit, somebody made a post discussing Rengar's rework, and ways to fix parts of his kit. A Rioter responded to the post with the comment, "Q: Nice meme." in response to a suggestion a person made. Basically, they shot down the suggestion with a snarky comment, and of course the board went wild. Never have I seen Riot fuck a community so hard. Rework a champion to the point where half of the people who played him now hate him, and then say that he's fine and that the community is wrong for wanting him to be fixed. At least with Kog'maw, they reverted him. At least with LB, they admitted they fucked up, and said they were working on a fix. At least with Malzahar, they spent an entire year trying to fix him before partially reverting him. Rengar rework is the equivalent of Riot saying the Malz was going to be a Midlaner, but his rework moves him to support. Then, they say that him becoming a support was the goal the whole time, and that him being a support is the direction that they are going to take him from now on. If they did that, the community would QQ about Malzahar for years to come, like how Karma mains are. Except unlike Karma all of the big boards people would be QQ'ing as well.
Speaking of Karma, her rework was the only rework that has ever come close to this level. At least the Karma rework was several years ago when Riot was still trying to find out how to deal with reworks, and at least they don't ignore Karma mains and reply to them with passive-aggresive comments.
TL;DR: Rito gave rengo mains a big middle finger. At least LB, Kog'maw, and Malz got some follow up work. At least Skarner, Garen, and Morde reworks were considered failures.
Source for Q: Nice meme: https://www.reddit.com/r/Rengarmains/comments/5me2gt/some_thoughts_from_rengar_tweaks/dc33qke/
Source for Of course he's going to be an assassin: https://boards.na.leagueoflegends.com/en/c/developer-corner/hYn5EO3E-assassin-roster-update-rengar-direction?comment=00050000