First off I'd like to ask what rank you are. Secondly, I do understand that one person can lose the game for everyone, very stupid mistakes still happen in high Gold. But I recall when I first started playing League a bit over a year ago. I wasn't a good player. I deserved Bronze when I started doing ranked, and so I got put in B4. Eventually, I got much better at League, and was able to climb to Silver and from Silver to Gold. I think the problem is you might (I've never seen you play, but this is talking about people in general.) have decent mechaniks to at least hit Silver but you don't understand the game and how it works well enough to carry. I remember when I was low elo I understood that if you get lets say 2 kills or 3 kills ahead of someone or the whole enemy team in general, YOU HAVE TO USE THAT. If you don't use that advantage then what was the point in getting it? However all of this being said I do agree that AFK's and feeders or a team who just refuses to work together whether ahead or not does affect the game.