The matchmaker is being worked on as we speak. It was supposed to get an upgrade 2 patches ago, but a major issue prevented that. Unfortunately, it will not magically get perfect overnight, partly because the worst results affect only the best players (i.e. a minority), and partly to keep it from getting even worse (I hear it was worse). You can find out more about MWO, including the matchmaker,
here. Read before posting -- a lot of questions and ideas are already covered.
If you often experience winning easily or losing despite getting great personal results, then congrats, you made it to the "carry everyone or else" skill bracket. This is where you really want to join or build a team as 4 > 1. Scroll down to the Factions subforums, and take a look. There are both ver casual and hardcore competitive groups.
There is a bug that can make you commander if you happen to hit space on the ready screen.
People will start moving to good locations immediately. If you do not move, you are assumed disconnected/AFK and left to yourself. It may be better to cancel searching if going AFK, there is now a button for that.