I like what @KeI143 said below. yes every time Riot starts a new season things are really bad for a few months. This is because Riot needs an excuse to reset players rank to match their hidden MMR. Throughout the regular season a great majority of players rank up higher than their MMR. No fault of theirs, it is an issue with Riots system. Either the MMR rating does not actually match the players skill, or more likely the system is full of faults and they just have to reset it with a band-aid instead of trying to resolve the actual issue.
Anyway yes it is terrible for roughly everyone. You have much higher tiered players getting thrown in with really bad ones and either lose because they are too heavy to carry, or players get a free win because they are lucky enough to have that person on their team.
I had two ranked games Saturday night. One with a guy going teemo jungle. He died to the 2nd camp (you can imagine how that went) and a second game in which our mid laner was AFK for the first 22 minutes of the game.
Almost everyone has stories like this. The teemo pick wasn't a bannable offense. I am sure people on my team reported him, but he didn't break any rules. He wasn't running to lane and simply feeding to throw the game. For some reason he had a good game at one point in time and he thought Teemo jungle was the best thing ever. He was very wrong, but again he didn't break any rules.
The mid laner going AFK for 22 minutes... Was against the rules. Who is to say if he was not just standing at the fountain clicking the "I am not AFK button" or if he really was AFK. He did eventually DC and he did eventually come back, but of course by that point the other team was way to far ahead. Did he get punished? I will never know.
I do know that in both of these cases I lost LP at the same amount I would of if it was a straight 5v5.
The sad truth is everyone has plenty of games like this. Everyone has stories. These are just two of mine from one day. Could Riot try to do more to make the gaming experience better for everyone? Yes they could, but Riot's policy is they do not implement things that exclude or ban more players than they otherwise would if they made no change.
My advice to you is try to find people of equal rank to play with. This is extremely hard to do even after 6 years Riot has not implemented a system to help you find people to play with. Last I heard they were looking at implementing a social system to help you chat with your buddies and integrate their the app. Or in other words they are trying to create a system to replace something that is already very simple and used throughout the world called texting and whatsapp. The other sad truth is whoever you find and queue with will likely rage and leave your queue group if you ever lose >.<