This is an issue that many people are not directly effected by, and yet it is the reason for countless threads by players who protest individuals who smurf and the impact they have on games. Specifically, smurfs tilt the balance of games, ruin peoples precious mmr, and ultimately make it an unpleasurable experiences for all - even the damn smurfs.
So, why do people smurf? Well, speaking from firsthand experience, I smurf because I can't manually join a single game. I just want to have some fun dammit, and fun to me isn't being limited to a CRT for a dozen hours of play, and yet because of the current matchmaking system, my main account is forced to auto join which can take 5+ minutes. More often than not, it places me with players who are stuck in the very low mmr bracket (Sub 1200) who also have trouble joining games. Through some simple observation using the hawken server app (made by Shadeness), I have noted that players are only able to manually join rooms that are 500+/- your rounded mmr (ie. 2520 mmr is considered 2550 in the app/ingame).
Here's the issue. If a player with 2600 mmr wants to join a server with an avg. of 2000, he must use the auto join feature. In the unknown elapsed time it takes for the game to place him into the server, the typical result is that A. the server gets filled up, or B. it places you with other lower tier players who are also having trouble joining a server. The fix is simple (atleast on paper) - if you can't manually join the highest available server in the game at that time, then the matchmaking should place you into a room that is closest to your skill level - likewise with the lowertier players.
Now, I know some people have this opinion that smurfs are the devil and that these smurfs are beaming with ecstasy from blowing up casuals who haven't even figured out the dodge key. I can't speak for others on this matter, but I know personally I would much rather use my own mechs and layouts, and have the matches I join balanced accordingly based on my skill level as to prevent a complete stomp on one side. That's all I have to say, the rest is up to the devs. to decide how they should go about this issue after they are done settling in.