Diamond 4 in Silver MMR

Yeah yeah, I know, its norms. Its still kind of dumb.

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2171565642/227626507

I'm Rengar ADC and the Thresh is Diamond 4. Shouldn't Norms MMR be balanced at least a little around Ranked if you play it mainly? Like Silver Ranked can be matched with Bronze+, Gold ranked can be matched with mid-silver+, Plat can be matched with mid-gold+, and so on and so forth. And thats just for spread out games. Why am I getting a support from 4 divisions above me(21 ranks!) to carry the crap out of me? Like, I'm not complaining, but I imagine I'd find others like that. Heck, I already have. I found some Diamond player playing I think it was Lee Sin bot lane in norms in my game and he was so good we never stood a chance(~)

I get norms only players rising in MMR so that a player with Diamond skill isn't based in Silver MMR unless he does Ranked, but why are players being matched in a lower norms MMR than Ranked?