Talking from personal point of view, but might be the case for many others. A bit ranty with an extra dose of salt, so here it goes:
League is slowly losing it's appeal for me. Some meta reinforcements here, some gimmicks removal there, some completely random stuff. While one of those is not a big deal, they add up. Tying xp gain to jungle items, making it not worthy for laners to take an early camp and making almost impossible to jungle without it. Capping pots. Removing mana pots. Adding those plants.
Things have obviously changed. Some people liked the changes. Some didn't. I'm on the second group. I see each change as a blow to off meta picks and strategies, two things I've always enjoyed in any game I've ever played.
What kept me on the game were a two champions:
Shaco, who I've picked up way back in season 2 when I was lv 19. I've played the shit out of him and only him way before I even knew what a main was. He's still my main.
Singed, because he has the most unique play style in the game and is obnoxiously fun.
Those two champions have been my go to picks for any time that I'm stressed and need to relax, or got tilted and need to have actual fun during the games.
Making big changes for them is a huge blow to my enjoyment of the game, specially if the changes are huge ass nerfs under a different name, as it seems to be Shaco's case.
When champions are the thing that makes you enjoy the game rather than the game itself, big changes to them are a problem.
It may be just me, but if I were to bet I'd say a decent part of the community feels that way.