Need Adjustable LP/MMR System Based on AFKs

Riot NEEDS to implement a system that make 4v5 or other uneven games reward less LP and MMR and removes less LP and MMR based on the difference in active players in the team. Yes people can abuse this by actively keeping themselves in game, but that means AFK reports need to be more harshly punished.

 Why should we lose the same amount of LP/MMR if  my team loses and has 1 or  player on my team afk to the point of them having a red afk name in the results page? And why should the enemy team with the player advantage get full LP/MMR when they win a 5v4 if the odds are in largely in their favor? If the 4 man beats the  the 5 man then reward and remove the normal LP/MMR amounts, but don't punish the  4 man for losing and reward the 5 man for winning.