The reason why the Leblanc nerfs to her W are a bad thing and a bad choice for gameplay
as a quick tangent i work in the game industry and have for 6+ years so this doesn't come from just some random guy on the internet, i do have experience in this area.
now i've been a Leblanc main since i really started playing this game in season 2. i played in beta but i didn't pick the game up until i discovered Leblanc way later. At the time she was considered a terrible champion to play but the reason why i played her and the reason why so many did is because her kit was fun! this had to go with the feel of the champs design. that feel didn't revolve around the power of the champion. i didn't care about winning as much as i did having fun. if i wanted to win there were better champions at the time to learn but her kit was so fun i wanted to master it. to put it in simple terms when it comes to balancing this there are two things to really balance:
**1. ** the numbers in which controls the players movements, speed of the spells, and the rate at which they travel. this is what most people would consider "feel" of the champion. these numbers are crucial because even without applying any damage they should feel powerful and fun to use even if no other champion is around. when values for these numbers are found they should almost never be changed. even slightly too fast or too slow can ruin an ability.
for instance, the first super mario game for nintendo was one of many platformers at the time but the reason it succeeded where others failed is the ingenious design and number tweaking behind the joy of movement controls that made it feel fun.
2. Damage, and cooldowns, these are the numbers that do need to be tweaked constantly. the best balancing comes from the controlling these two numbers. while the numbers for feel really don't room for how much you can take away or give these numbers are extremely malleable. these will most likely determine the champions viability as a pick but will not completely deter people.
now this is incredibly simplified but you get the gist.
so the problem with Leblanc's changes to her W are similar to what i see in Riven's windslash. it no longer feels powerful and looks as impressive as it used to be. i'd much rather the damage be nerfed on these abilities than having the speed at which they move be nerfed. when you nerf speed at which abilities move you're taking away the fast paced fun. damage comes regardless and people have been playing champions that have been considered not viable even when the damage is nerfed. for instance Diana is seeing more play now but even after she was nerfed i still saw some good Diana mains in ranked because her kit still felt good. unfortunately for Leblanc her kit now feels clunky and slow as most people have found out. those i knew who main her don't anymore because it's not just that's she's not viable, she's also not fun to play. champions that are not fun to play and clunky rarely ever see play even in norms which is why the older champs are usually forgotten. a good example are the changes to sion. it's not just that he seems stronger now it's that his kit is fun to play and feels powerful. i just don't want Riot to take away the "feel" of the game because it's what always separated itself from Dota, HoTS, and other mobas in my opinion and it's what has made it so huge. now league isn't perfect and there are so many ways to improve the feel of the game all around including on Leblanc (as fun as she was to play she still wasn't perfect either) but we shouldn't be taking away from it.
this has been sort of a slow trend that i've seen the Riot design team do for league and honestly because of it after this i won't be supporting League anymore. i might quick hit diamond before i quit because it was always a goal but after that i plan on quitting and i for sure won't be spending money with them any longer. the one champion that made me fall in love with this game is no longer fun to play and it has nothing to do with her damage or viability. i've played her past all her nerfs, her buffs, and everything in between. regardless if she was a good pick in the meta or not. i know i'm just one customer and i'm sure i'm going to see a lot of "QQ you just played an op champ" type posts or "just play someone else" but that's not the case and although i've played all the other champs i truly loved Leblanc's fun and playful design. it's one of those things i think riot should realize and in hopes they don't continue down this path of what they consider is balanced gameplay. instead look at fixing the champs and spells that are clunky and nerfing or buffing the damage output to make it match how it feels instead. at least that's what i would do.