We should NOT lose LP when people AFK.
When people come into a game already on tilt, and decide after 1-2 deaths that it's time to "derpderp AFK time", I shouldn't be losing 17-20 LP from the nearly inevitable loss that follows. That's utter bullshit, and heavily takes away from the experience of trying to rise through the ranks.
The system even DETECTS people that AFK; I'm certain you guys could manage setting up the system so we don't take an LP loss when this happens.