I completely agree with iosis here. It was a huge dissapointment when I saw that I was not able to compete with a friend. Sure you can boost each other to get better rankings, but I, as well as most of the people commenting on this post, don't care about it. It's great to compete, and if you can have fun with a friend while doing so, it's so much berter.
Maybe CM could adopt a certain policy like put the pair of players playing together in a room based on the rank of the player that has lower ranks (safety rank mainly). That way, players with S safety rank won't have to deal with a D-rank