Why doesn't riot keep LP for teammates of AFK's?

All of us who play this game make a concious decision to start a game knowing it is likely going to take at least 30 mins of our time.
Why do we play games? - Too have fun, Of course! Why do we play ranked? - Too compete against others who want to know how good they are and really push the game to the strategic limit that is LoL.

That being said, when i queue up for ranked I'm in it to win it, putting on my fake smiles telling my teammates to keep up the good work even when they're down and clearly making poor plays. Because that's how you get people to WANT to help YOU to win TOGETHER. As long as someone on your team is trying their hardest and trying to cooperate with the team, I don't mind losing. But AFK's is a whole different scenario. There is nobody there in the body of the champion. There is no ally. Some could argue that it adds even more strategic diversity, which it does. But shut the hell up because even if you like a challenge, a competent enemy team will have no problem securing their advantages.

So what happens when a player AFKs? - They get penalised so they can't play again for 15 WHOLE MINUTES. (I understand it scales with how often a player AFKs) Besides that they're free to go on their AFK tyrant destroying great games and reducing them to piles of smoldering bullshit laying across my computer screen.

The worst part about this is the LP sysytem in solo que. I win one game and receive 23 LP (Sweet!).
The next game a player AFKs and we end up surrendering at the 27 minute mark due to irrational teammates. And i end up losing 17 LP.
Such random numbers that our LP are based on, and you HAVE to achieve 100 LP.
Losing one game forces you to win another game JUST to get to the point you were before losing the previous. Thus, every loss puts you back AT LEAST one win, which is fair.

What really destroys my motivation to play ranked is that when I lose a game where it is irrational to even think that i would win I have to pay a huge repercussion. I not only think about my LP loss, but all of the time that this one AFK person costed me. 2 games worth of time of MY LIFE. I don't have everyday to binge play LoL.

What I'm requesting is that if you go AFK (And Riot IS aware of this, as we can tell from the punishments already installed) you lose LP the equivalent of two losses. And your allies receive no drop in LP.

Riot knows how difficult it is to rank up when battling with incomptent and uncooperative teammates. I'm not sure if they want to intentionally make it this difficult, knowing that I love this game so much i will pursuit the higher elo's despite how much BS i have to trut through.

So Riot, this adjustment would make the experience and lot less roller coaster-y and hopefully i can have more games where I can lose thinking to myself I deserve to lose.

And to any random people who have read through this whole thing, thank you. Even a comment like, "I Agree". Will mean a lot to me.

GL IN YOUR FUTURE RANKED ENDEAVORS.