"Positive players win more games" they say

In every game I encounter afk, toxic and childish players. I'm one of those that actually try most of the time to stay positive and play the game until the end, and I mean when the enemy gets to the nexus. But come on really what riot quotes when they say "Positive players win more games" that's a lie and I have prove and experienced such moments in this game to say it. The system will never change there will be always the same kind of players in mostly every game. In most of my games I always do really good, but there is always something negative on the game, and the most funny thing about all this is when you are very close to go up the ladder you always but always fall back, its funny because it is like the system works that way and most of the time against you. I have noticed that after going to another level in your ranks you always encounter negative and toxic players, is like you are only able to get to a certain level on ranks and wont pass further. No matter how fed you are, or how positive, you will always get stuck on the same place. So S8 wont be any difference.