Why do good players have to carry bad players?

I have been positive KDA in last few games get players who are below enemy team level y do you expect me to carry put me in the same division as my elo stop making me go 8/1 and have a chogath 1/10 ? Im getting the team with 40% win and enemy 54%????? WTF im only 50% win rate i cant carry a team with 43% win when they tower dive and the entire team has a 54% win rate and you demote me? WTF IS THIS. you put me in a premade of 4 players i go 12/3 and they tell me i suck all game i dealt with it and i got reported LOL! WTF is this game ! y do you want me to drop in elo GIVE ME FAIR GAMES or PUT ME AGAINST PPL IN MY DIVISION NOT MMR RATING CUZ MINE SKY ROCKETS CUZ EVEN WHEN I LOSE I GO POSITIVE, Ya we have those off games but i'm a try hard and try to help the team everyone gets Tilted but for the last 2 days before school starts I SEE 40% players on my team bronze elo and the enemy team 54% gold elo? WTF IS HAPPENING I HAVE SCREEN SHOTS OFF OP.GG IM GOING TO COMPILE THEM