What are you talking about? Yes it was strong (not TOO strong though). They took away 60% of it's damage. Her old miasma within the full 7 seconds, 9 ticks of damage, used to be one of the highest damaging lvl 1 abilities, at 225 dmg without AP. If you have someone stand in your W for that long now you are within the lowest 20 lvl 1 damaging abilities, at 90 dmg without AP....that's like the polar opposite. Standing in Miasma used to be relatively scary, now you are just annoyed by the slow.
I also don't understand what you mean by the last update "hitting the spot" of the rework. The only thing that changed was more damage. The hatred for the rework was almost never about her damage. her playstyle now is still a pain, It's not fun, her theme is disgracefully ignored and they keep putting bandaid fixes on a blistering gash.
The milestones are very different from Viktor's.
He has a diverse playstyle. Having normal AP ratios on every single one of his abilities, using any of them hurt his opponent, and he can focus on using one as his main damage source the entire game. He has great wave clear, strong throughout every portion of a game, and his main identity is intact.
Cass has bad ratios on 2 of her 3 main abilities. She doesn't win lane ever. She has lost her gaming identity. She is bad at poking, bad at bursting. She used to be one of the scariest champions for her AoE and Single Target damage, you literally cannot focus on poking now because after 30 minutes, her Q and W damages are negligible.
Unlike Viktor, most players can't enjoy using her because her playstyle went from acceptable and unique to boring. Who feels better to stack with Cass, or Veigar? Veigar feels every stack.