Why are the teams so unbalanced?

Can anyone give me any logical reason as to why I ever have to play against people over a division above me? I'm silver 5 on the verge of bronze and I play against gold players in just about every single one of my games. And that's just the average game. When things get really shitty I find myself playing against plats or even diamonds. Its so infuriating for the game to be over before its begun because the other person is better than me in every possible way.

And nobody give me that bullshit that "its mmr and not about rank," because that doesn't even make sense.

a) What causes a gold/plat/diamond players mmr to tank so much that he's playing against bronze players? b) Why do I have to have a shitty game because he's on a lose streak? (basically why do I get an auto-loss because he's been having a bad day) c) EVEN IF we say that the matchmaking system is fair because it's based on mmr, is there no one my skill level that I can play against?

This one pisses me off the most because an article from 2014 said that there are 27 million daily active players every day, and 7.5 million players playing at the same time during peak hours AND I'm in silver 5 where the majority of players are. So out of the vast majority of players they COULD pair me with... they decide that balanced teams would be 2 golds + plat + unranked vs 3 unranked + (me the silver) + a bronze. Or 4 golds + plat vs 4 silvers + unranked. None of this makes sense and I wanna know answers as to why this happens so much.

I guess my TL;DR is: Why does league use a matchmaking system that consistently does a bad job at judging player skill and team balance?

(this applies to norms as well as ranked, but right now I cant play normal because of this happening so often. So I have to practice new champions, builds, strategies in ranked because if I go into norms its almost guaranteed that we lost due to this very issue..)

Edit: Whoever removed my post clearly didn't read it and only saw the title... It originally read "Is there anyone my rank I can play against?"