Matchmaking Confusion

So before I get into this I'll admit some stuff. I was getting tilted during the match about to be mentioned. This is not meant to be a salt post.

Getting into a recent match I had a Morgana who was playing exceptionally bad. Being the salty g5 0lp player I am I was pulling the "what the brown" card. My salt continues some until my Talon tells me that she's not even level 30. That really catches me so I zoom off to op.gg real quick to check and I see that Morgana and Ryze are as Talon said, not level 30. A couple of the enemy were the same.

My question for anybody willing to answer is how did I get put into that match? I haven't played with pre30 friends recently and since league is as popular as it is, why did I get put into a match with pre30 players? I seriously doubt that there was nobody else they could match up against, even if they were playing with a friend who was level 30.

Thanks forums,

Cyrusklep