Back during the Bilgewater event there was a glitch with the new HUD that was causing lots of people to dc from games. I was one of them and I dc'd from every game I played, however I was always back on as soon as possible (would only take a minute or two to load back in)
Now, why didn't I just wait to play? I was going on vacation a couple days after the event started and wanted to play as much as possible to get the rewards I could, since I wouldn't really be able to play on vacation and who knows how good hotel wifi is.
Before the event, I had NEVER been punished. No Leaverbuster. No chat bans. Nothing. Because of the glitch causing me to dc, Leaverbuster punished me, and ever since it has not left me alone. There was a week where on 2 separate days I was playing and had time to play, but something came up and I had to leave the games. Before those 2 games I had not left a game in a very very long time. Leaverbuster immediately busted me and I had to wait 10 minutes before each game.
My problem with Leaverbuster is that it can't tell the difference between the game crashing, and someone leaving or ragequitting intentionally. So then people who's games are simply acting up end up being punished the same as a ragequitter would as far as LEaverbuster goes.
The Bilgewater thing drives me nuts whenever I think about it. Yea, I understand you are in charge of your connection and wifi, but RIOT is in charge of their game. They had the HUD being tested on the PBE for a while, and then it caused that major glitch with a large chunk of people when they released it. They tried to run a huge event and install a brand new HUD at the same time, so the glitch took a while to fix because they weren't sure where exactly it was coming from. It could've been coming from something in the event, or the HUD, but it took them a while to find it because they added lots of stuff all together. I know I wasn't the only one who was Leaverbusted during that time. My connection was fine, the game was not.
I've only ever left games due to unplanned circumstances that cme up (like a couple weeks ago, my dog threw up while I was in a game. Let all my teammates know and I sat my champ in spawn while i cleaned it all up. Didn't actually dc from the game but was back within a couple minutes and everything was fine. Teammate even asked how my dog was doing (she gets into stuff every once and a while and finds a way to get it no matter what you do ._.))
I've never left a game because of toxicity, I've always just dealt with it.