Accept the fact you can't change the loss
Seeing how one person can afk, stand still in the middle of a fight, feed a little then stop, or trade in deaths and have more control over a match than a player carrying hard. I have Accepted it. Now I mute chat, and pings. If I see players making very bad choices repeatedly I stop caring about that match, and let them 4v5 the rest of the game. In reality as long as you push the lanes farming, and sneak a kill here or there your not breaking any rules and no one can report you.
The reason why one player throwing a match has more power over the player carrying hard is because Riot has made the game all damage, and cc. Riot does not like the game play they use to have back in the day were you had tanks, Zoning, Timing, and other tools that allowed any player to carry them self's. They want players to work off each other. So because its so team heavy, and less solo it makes it very very easy to force a loss using just one player.
If part of a chain breaks all others start to break as well because they can't hold the weight. You can still have fun with the match even if your going to lose, and it is funny watching players spend the rest of the match spamming all chat over playing. So I would agree with many people who find it entertaining watching players spam and make mistakes over trying to play smarter.
League has been like this for years now, and its not ever going to change. So if it won't change find your own fun in the game. Even if your going to lose Grab your popcorn, and just enjoy the show the team will put on for you. Its more fun to me over stressing out about how I can get my team to kill the correct player. Besides we know Riot won't bring back the old game style. So its not like you have to worry about them putting a dent on your new kind of fun.
[slayer-pantheon-popcorn]