Why am I playing with platinum ranked players in team builder? (Silver 4 is me)

Granted, I play a ton of Gayren in Team builder, but i'm silver 4 for a reason. I don't care about getting better, I just want to play a game with other terrible players like me, have a fun game, then log out. It's becoming consistent too. Should I just play a different champion? Is the hidden MMR tied to the individual champion or to my summoner name?

What's also interesting is how much more immature the higher the rank the players are. Seems like a reverse.