Do my team-mates suck or are the enemy just too good?

THIS IS A LONG POST, BUT IT'S MY FIRST SO I'D BE HIGHLY GRATEFUL TO PEOPLE WHO REPLY AND PROVIDE THEIR OPINIONS AND FEEDBACK. THANKS IN ADVANCE GUYS :)

How does the match making system work with league of legends when we opt for normal pvp games? I don't know why but i keep getting placed with people who refuse to communicate and work as a team. No coordination AT ALL!

I mean it's been going on for the past few games, most of which iv won but a lose doesn't feel good does it even if its just one?

last 6 games. won 3, lost 3. reason for losses for the games:

-> got stuck with teemo both games

-> In the first game he wouldn't let me farm! he kept hogging all the minions, he even went to an extent that he would leave his minion and claim mine and then move on to claim his as well!

->In the second game, the teemo let the other team get first blood, but he wasnt really bad with respect to game play, he just wasnt there as support or as anything when i needed him, he was trying to jungle even though he saw enemy approaching, i was actually doing quite well with 3/0/1 when he started running off to jungle and being i couldn't do much as im highly squishy and we eventually lost a tower bot (this all happened within 7-10mins of game play). Now in this game teemo wasn't the problem, it was the top laners, Darius and Vi going duo top against caitlyn and jax, and they fed like crazy! I told them to try and farm near tower and not push the lanes too much which would help in decreasing the deaths, but they didn't listen! they kept going and laughing about their deaths and when they had too much they said "will nobody else who doesn't suck come top and help out?" (argh!). And by the time the game moved onto team fights, jax was pretty much dominating it all with a quadra kill (his penta got stolen by yasuo). First they fed, then they kept surrendering when they couldnt control it anymore!

-> For the third game It was my fault we lost since i wanted to try out blitz and basically that game was my first support game and first blitz game but even in that i was top with master yi and i got him plenty to kills.

Now even though i won the other 3 games, it's still highly depressing when your support doesnt help you out and u end up dying being a squishy champion. there's only so much an ADC can do alone... know what I meant? lol

I'm not saying I'm skilled or anything, i barely know anything about the game compared to most people who are playing ranked or something, but i would like to know why the system places me with bad team-mates against good enemies who know their way around?