New afk system?

Since there is some people that have to leave/salty and leaves the game but dosnt dc, i think there should be a system that if the summoner is staying in the fountain for over 3 mins even though they are moving a very tiny little bit should be dc because the 10min afk thing can be avoided by just pressing some key/buttons and it is just sad that there just there doing nothing/trolling and nothing happens to them. Yea after the game the afk system give them penalties or whatever it does for the time they have been doing it. Hopes it does something to change the mood of the players.