Why do you not get xp for a teammate afking in a rank game?

I played a rank game earlier, and my top lane ended up afking for some reason though I got no xp. Riot you may want to look into that, and idk how harshly you are punishing people who get stuck with a afk, but I personally don't think you should be as severely punished for losing a ranked game with a afk teammate. I assume most of the community also agrees, but let me know your thoughts, and how badly you are "punished for a teammate afking, and you lose the game".