Rationale Behind a Separate Queue for People Who Rarely/Never AFK
TL;DR - Designing a separate opt-in-every-game queue where AFK'ing for any reason results in automatically being removed from the queue would improve the quality of life for players who rarely or never go AFK.
Preface: I have never purposely AFK'ed.
Some players in League see AFK'ing as a valid option. They see it as a viable way to shorten the amount of time they are "stuck" inside a game. Whether simply sitting at the base in ARAM while the enemy team wrecks the inhibitor and nexus turrets, or literally disconnecting from a ranked game to go play on a different account, in every case their actions affect the rest of their team.
LeaverBuster is not currently effective at minimizing the amount of AFK players. AFK'ing especially seems to be far more common in the "lower priority" games - ARAM/etc. Even at high levels and tiers - level 300+ - there is more often an AFK player than not, on at least one side of the map.
I think the League community would be well-served to have a separate opt-in queue where players commit to not AFK'ing under any circumstance, and to taking actions to prevent going AFK at all costs.
It would be structured simply, and have some type of major consequence for going AFK. Going AFK would be defined very clearly, in a way that could be easily measured and not easily be abused. The queue would only be available to characters above a given level, so that removed players could not easily get back into the queue by making a new account. Players would have to commit to not going AFK before they could click "Accept" on a new match. Going AFK while playing a game in this queue could remove your ability to enter the queue. Forgiveness could be an option as well - perhaps players could regain their ability to enter the queue after 10 games in the normal queue where they do not AFK, and submit a written explanation of what they have changed to prevent AFK in the future (improved your connection through wired vs wireless, committed to not playing during times you have other commitments, etc).
Determining if a player is AFK would be based on reporting from other players, along with current methods. Any player reported as AFK would immediately receive consequences; in each case, the game and all AFK votes would be saved for potential further review. The reported / removed player could submit evidence that they were not in fact AFK during the game. Players who are found to mis-report another player (call them AFK when in reality they are simply a poor player compared to what they desire) will be removed from the queue and permanently lose their ability to report players as AFK. Since AFK will be clearly and easily measured, it is less likely that incorrect removals will occur unless someone is abusing the system - in which case they get removed and lose that ability.
In the current setup, going AFK during a game sometimes does absolutely nothing to a player. In worst case scenario it requires waiting for a few minutes before you can play again. Very rarely does it get people banned, and in every case those actions require the interaction of humans. A system that imposes penalties and only removes them with human interaction would be much more effective. Harsh? Yes. But sometimes it is better to be Illaoi than Janna.
If purposely going AFK, or misreporting an AFK, could easily get you kicked from the queue, no one would do it.
Yes, we need a system that allows for true emergencies (like the house is on fire, or someone is dying), mishaps (your ISP experienced a power outage), and eventual forgiveness (people can change). But those are rare, and should not be the rule. They should be rare exceptions that require evidence and human interaction, not the other way around.
If 300+ level players are any valid source of information, the current system does very little / nothing to actually fix the problem or motivate change.