lol
First of all, if you want to be so selfish in your view of things then think about it like this. Being rude to someone and telling them they suck does them, nor you any good, it puts people on tilt and makes them pissed at you. When people are pissed they play even worse, you are not doing yourself any favors by commenting on how poorly they are playing, if you want them to do better then you should be ignoring their failures, and when talking about mistakes say things like 'we need to' or 'we should do X' not 'You need to' by generalizing and making it about the team rather than the individual they will be much more willing to comply than if you single them out in front of everyone.
Second of all, I know for a fact that you do not play well in every single one of your games, if you did then you would be challenger. Everyone has bad games and getting pissed at someone because theyre having one is pointless.
Third of all, (and this goes with my previous point) Matchmaking places you against people that are around your skill level, if you are in the same game as them, you are NOT better then them.