Unjust Punishment
In my last game, I was at 0LP after a couple of bad games following having recently gotten promoted. In this particular game, we started with an AFK support and an invade from the other team that led to first blood on their side. Our support came back right before the remake period; this isn't a big deal. We all know that sometimes the client bugs and it can take a little longer than you'd hope to get into a game. Shit happens.
The problem came when our jungler suddenly disconnected. I don't think it was intentional - he was preparing for a gank and suddenly dc'd. The problem here is that we proceeded to lose a hard-fought 4v5 game, and of course I was demoted.
I'm sure I'm not the only one this has happened to, and I know that someone will understand when I mention how discouraging it feels to have seemingly wasted time and energy on a match like that just to lose LP, rank, and MMR at the same rate when you have a player on your team who disconnects. The system is clearly sophisticated enough to determine when a player has left, because it shows you their icon crossed out at the end. I'm not even suggesting that he should be punished, because these things do happen to everyone on occasion. But why punish players who did nothing wrong?