What is this matchmaking?

Our team had a Zed with a 31% winrate in ranked, two unranks, and One Gold2 and one Silver 3

Enemy team has all S1 and G5 players.

I ganked Zed FIVE TIMES in the first 6 minutes of the game, and he never went in, never did damage, never ulted. This Rakan was working his ASS off to get this Ashe a kill, she just wasn't having it. She walked into 3-5 people alone a lot of times.

I don't understand why Unranked players are allowed in these games