Reworks cam be done for a number of reasons, whether it be the champion doesn't work thematically, is too hard to balance consistently, has an out-dated kit, etc.
That being said, I'm seriously sorry your champ got reworked, No sarcasm :( . I've always hated the concept of reworks, regardless if they actually turn out good or not. Even if a bunch of people like the rework, it's alienating others who were loyal to the original.
It would be really nice if they just made "reworks" like skins in the sense that you could choose which kit you'd like to play with. I know this doesn't do a whole lot for the game regarding consistency and knowledge, but I think more people would end up being happier in the end. If the champion was a real problem, they could just have their numbers nerfed (potentially quite a bit) to the point of being left in a weakened state, if only to let people who want to keep playing that champ with that kit keep enjoying it.
Might not be super practical, but I think the playstyle is what makes a champion so enjoyable, the way certain things work together. Not necessarily their damage. Speaking for myself, if I had to choose between a dramatic nerf on all my damage or a complete rework, I'd choose the former every time.
Bring back old Karma :( (and friends...in a form of my idea listed above so everyone is happy :( )