Matchmaking balance riot?

Why the heck, is it when i try to practice in a normal match, do i have 4 silvers along with me (previous gold) agianst 2 a silver, an unranked, and 3 diamond players? how is that fair? ive had to play against a plat, a diamond smurf, and 3 diamonds in one game today? what makes you think that this matchmaking system is ok?!?!?!?