I think you're seriously misunderstanding people's hate.
This has never been a "mashup" game, like Tekken vs Street Fighter, Super Smash Brothers, Jump Superstars, etc.
If these had been established characters BEFORE, and LoL had come about as a "hey, see your favorite characters beat each other up!", THEN you would not need a reason and could do what you're doing.
But that's not the case. The fact is, this game IS, and **should** be tied to the characters. No Summoners? Fine. No Institute of War, AKA League of Legends, for which the game is named?... What? I don't even. Just make a new game if you guys are bored of making LoL, don't trash this one's history.
I don't give two shits about axe-wielding soldier man, I care about Darius, the supreme embodiment of Noxian Ideals, who joins the league as an outlet for warlike tendencies.
I don't give a fuck about some Darth Vader impersonator, I care about Kassadin, the man who has seen the void, who lost his daughter to it, who was warped by it and joins to the league to fight vigorously against it's impending invasion.
For starters, in a game called League of Legends *the League of Legends **is** core*
Second, *nobody cares about these characters when they're just random people who do stuff in a world*
Third, *providing no explanation to the 5v5 game, I don't care how you justify it, ruins the game, kills immersion, devalues characters, and is a bad decision.* No matter what "lore" you do unattached to the game, it will feel like a spinoff, because it will be a spinoff.
I understand if you feel the Summoners and Institute are restrictive, because they are, because **that is the entire point of their existence in the world**.
If you want to tear down the League, then do that. Make it an event or something. Make the first faction battle you guys have done in years, and through it bring the downfall of the institute and the summoner system. Have the world begin crumbling to the magic that is now going rampant, that the Institute was designed to stop. Do whatever. ***BUT TIE IT INTO THE GAME***. Without being a part of the game it's pointless, because the game ***is*** the "core" of League of Legends' lore.
Make the world into one at war, like it would be without the institute. Make Nexus' be insanely valuable wartime artifacts, allowing immortality to those who control them. Make the battles be about 10 champions fighting to gain control over each other's Nexus, destroying it as the only way to permanently kill the enemy champions.
Sure, it might be darker, but that will enrich every character. Ezreal's lighthearted, cocky nature (which, now that you've ruined the character described by making him "embarassed", his total removal from the game is all that can be taken away from him) would be far more meaningful in a world trapped in wartime.
The summation of what I'm saying is this: I'm glad to see real lore development, and I'm glad to see you guys willing to take big steps, and, frankly, I'm glad to see the summoners and institute gone, but **you are not enhancing the lore by separating it from the game entirely, you are ruining it**. There are a billion less constrictive ways to keep them tied together than the summoner's/institute, there is no justification for you guys saying "pshh, yeah, dunno why these 10 guys fight each other" instead of making a meaningful connection to the game *that started the lore in the first place* and the characters in the world.
Sorry if that hurts your dream of a League MMO or a League Movie or whatever (hint: it COMPLETELY DOES NOT, but w/e). That's the reality, however. You guys trying to disconnect the game and the narrative is lazy, and it is going to do nothing but cheapen both.
All that said, if you guys decide to take a better route, you have all the support I can provide you.
Just keep in mind EVERY time you guys have ignored people like me telling you you're making a **BAD** decision with lore, you've never done *anything* except completely disappoint the fans of lore you change. Particularly with regards to champs. Several friends of mine outright quit at Karma, who had been playing since beta. Had to convince my GF to stay after she saw how you immensely cheapened Anivia's character, and had to do it again just now with Skarner's character. *LISTEN TO US FOR ONCE, JUST ONCE.*