Now see, I understand that some people have unstable connections or have real life emergencies that cause them to leave the game and that is fine, it happens, nothing much you can do about it sometimes other things take priority.
Counter argument, how often do you see people who get tilted and will simply say they'll go AFK? and the reason for it is quite simply, the punishment for going AFK is the most minor of any punishment in the game unless constantly repeated. a minimum of 5 games in low priority queue and a count towards a loss. Something you can work around by simply listening to music or watching a video while in queue. Its so little of a punishment that whenever I queue with a friend in low priority or cooldown, I barely notice it because I usually watch videos while in Queue anyways.
Point it, the punishment to going AFK needs to be more severe, I'm not asking for players to be banned but something that will at least deter you from just popping out of the game whenever you don't feel like playing anymore. What this punishment would be I don't know but some change needs to be made.