Why to NEVER duo queue!

Maybe everyone is aware of this, but I want to explain mathematically why you should never duo queue. The way Riot's ladder is set up, they have your true rank (i.e. Gold 3), and your MMR (Match Making Ranking).

Each True Rank has an estimated Numerical Elo (Silver 5 - 1200), (Gold 1 - 1800), Etc. Your MMR Might be 1800 which is equivalent to Gold 1, but your true Rank might be Silver 5 (or 1200).

Riot's system will match you up with people around your MMR, as to see if you can win giving you more LP for beating higher level players. So, Lets say you want to Duo queue with your buddy.

His True Rank is Silver 1, MMR is 1550 so, Riot thinks he is Gold 5 Your True Rank is Gold 5, but your MMR is 1900 or Plat 4.

You play games, and because you are better than your friend, you carry him, climbing the ladder. Finally, your friend is Gold 5, and his MMR is 1550 or Gold 5... so Riot believes he has met his potential.

You are only Gold 2 , but your potential is Plat 4. You continue winning, and you get to Gold 1, and now your friend is Gold 3.

HOWEVER, your friend is truly only as good as gold 5. Riot system now believes that he is better than he truly is! Therefore, you will get paired with players that are even HARDER for you to carry against than if you had a teammate who was Gold 3, and was a Gold 3 caliber player.

Effectively once your friend realizes his potential.. you are smurfing him, but hurting your potential of climbing the latter to YOUR true potential. Duo Queue benefits only the weaker players, and will inevitably cause the stronger player to continually carry harder, until he cannot.

Thoughts?