Losing LP for a 4v5

Hey all. So I played 2 games in this last week which were kinda important and that I needed to win. BUT I didn't because some guy left halfway through the game. I was suggesting that if someone leaves during a ranked game, the losing team shouldn't have to lose their lp because it's really hard to win a 4v5. I think that the winning team should continue winning their LP like normal, and the afk should lose 40-50 LP for leaving, and none of the losing team should have that game count. It's just totally unfair to everyone who spends 30 minutes in a game just to lose because someone left their team.