i can't believe this

I was spectating a game..just for fun and i saw he was against a 5 man..it was 5 vs 5 ranked..all good and nice..but, but, holy fck, this is the players elo

my friends team P5 2-G4 2-G2

The enemy team

2- G1 1-G3 1-S1 1-S2

They played 2 games..guess who won??:))and guess how much LP they got? 20 fcking LP/game

Ok, this matchmaking not onlty that it sucks, but it's so unfair..how the fck can someone be plat if they plat vs silvers:|=))))))).

Such a fail system