Demoting/Losing LP from a game with a AFK in it

So I lost a game where two people afk'd and I demoted from it. This shouldn't even be a thing in all honestly, why should the team without the afk be rewarded (LP gain) and the team with the afk be punished (LP loss/Demotion). Should it not be a loss prevented or like 3 LP loss if your team has an afk in it? The current system is anti fun to play in cause if you have an afk, you insta lose and you would lose the same amount of LP as you would if their wasn't an afk.