Matchmaking issues? Unfair?

I was wondering if this is an actual thing or just some bug. I've been constantly getting into normal games as an unranked player against Plats and Diamonds. Sometimes I get an unranked ally or unranked opponent but I'm trying to see how is this fair. Just last game I was MF with my premade support Blitz (also unranked) and our enemies were a DIAMOND III Twitch with mastery score over 500 and his support Soraka who is** PLAT II**. It's clear that we lost and I'm not complaining about it, I'm just wondering how is this matchmaking fair? Is it an intentional thing or a bug since I can't remember if this issue existed before. I also once had plat Trynda top against an unranked Mao and the guy went 1/5, who would blame him. This is so lame. [slayer-jinx-unamused]