Making a casual mode impossible to play for groups of people is going to hurt the game long term. The devs clearly need to work on this implementation, thinking a 15~30 minute queue for people is the solution is genuinely insane to me.Valve has never talked about what factors are used to determine rank. It's never just win/loss and end game stats. You should've noticed that by now. Dota 2 and CS had the same treatment. It's too easy to game the system if it's known.
You're proving Valve correct in the way that you're talking about how you always play in a pair. You're playing every game with a significant advantage and that's finally being taken into account. 6 random solo players don't go into every game with that kind of teamwork. The fact that you're only now complaining about a challenge with bad teammates is how every solo player has been playing for the past +3 months.
Don't the 6 random solo players have ranked mode if they're so concerned about skill diff?