Because leblank rework was fundamentally a failure. Let me explain from biased leblank main point of view. Reworked LeBlanc got her Q proc moved to her passive with 1.5 second delay. This was supposed to even out her power and her weakness. Her power being, increasing her TTK to give you room for counterplay and her weakness being giving her better wave clear. On paper it sounded good. However in reality this achieved these things :
- Procing her mark was made completely braindead, all she had to do was dash on you, apply passive and then press Q from range. Most mid laners had no possibility of countering this, other than flash. Which is coincidentally literally same thing you guys are complaining about now. So that didnt change anything, only made her more noob friendly so you could see more of her. Compared to old leblank where she had to Q first and then either dash in straight line right into her target, which was highly predictable and counterable. Not easy to do but possible. Other option was hitting mark with her chain. That spell had its width nerfed so heavily that only skillshots with comparable width are nids spear, which travels much further, and kalistas Q which isnt all that important. If she missed, not only she just didnt deal any damage to you other than using her first Q(which is in most cases maxed after W) she just wasted a lot of mana. If you dodged her E, you literally out traded her with your auto attack.
- Gave her wave clear. Old LeBlanks biggest weakness was her lack of wave clear, this is why you maxed W first so you can kill wave and roam. After rework she could max Q and still clear whole wave in two spell casts without sacrificing her ult for full clear. This made decisions to roam much easier for players that werent so experienced, while made nothing to players that either camped mid and just pushed or were already good enough at the game in general that they did not need this tool at all. It only gave them more power early game.
- Gave adcs precious TTK to trade with her. However this went only two ways. Either LeBlank was so ahead, this change did not matter at all and with easier passive procing only made killing adcs even easier, or when they were both farmed equally, leblank just lost. Doesnt matter how good you played her, all adc had to do was right click on you and you couldnt engage without dying in process. This buffed smurfs abusing LeBlank in low elo, buffed bad players and HEAVILY nerfed actually good leblank mains.
- Her ult change was uncalled for and completely broke the vibe of her. Any LeBlank main stopped playing her at all since rework, only to come back after rewert. And the main issue was her ult. It was clunky to use especially since she was always the kind of champions where pressing your buttons as precisely and fast as you can made the difference between good leblank and bad one. Most people literally spammed her clone out of cooldown just to not fuck up their combo by pressing ult twice by mistake. It almost felt like riot wanted you to fail by implementing this mechanic.
So TL:DR, rework made leblank more noob friendly, so she was picked even more, made her laning even more unbearable, absolutely decimated her purpose as adc slayer, and mostly heavily nerfed good leblank players. There are literally handfull of good leblank players in each region and while you keep complaining about those 12 good players getting carpal tunnel every time they play her, fizz is sitting on 54% win rate in diamond + with linear near uncounterable kit. Nice focus guys nice focus.