Why riot won't address the AFK "problem"

Having played league for a long time, I can tell you that people don't just AFK for no reason. Generally, they afk because their team is not playing as a team or is being toxic and flaming. Ill give an example of why I have afked in the past and will do so again in the future under the same circumstances.

Top laner: picks nasus or yi or whoever doesnt really matter what champ, then WILL NOT leave top lane under ANY circumstances. Sorry but im not going to play a 4v5 because you don't know how to play, you deserve to and if im on your team you WILL lose that game. Im not about carrying idiots who cant teamfight into higher elos so they can ruin gold and plat games. If you find yourself having a problem with AFKers commonly, you are in the minority. Ask yourself why your teammates seem to afk all the time, and i'll tell you this, its not because they are toxic by nature, most likely you are in one way or another causing the afks.