AFKing in ranked and LP loss

It seems rather unfair that in a team game, if one person disconnects either from faulty internet or plain rage-quitting, their teammates should suffer. if someone doesn't connect before minions spawn in game, the game should either end right there, or the team with the AFKer should lose either reduced or no LP. I believe there should also be a slight reduction in LP lost if they DC before 10 or 15 minutes. That way, there won't be people exploiting the system by pressuring, or even DDOSing teammates to make them disconnect, as It is extremely hard to completely lose a game in 10 minutes.