High tier players smurfing in RANKED low tier games should be against rules, and you know it.
If you're SIlver, and you want to duo with your Diamond buddy, you should only be able to in NORMAL games. Go have fun. But never in Ranked.
If I am in Silver, and I'm trying to reach Gold, that means, in theory, I'm supposed to beat other Silvers to prove I'm above Silver league and belong in Gold. Every few games it's painfully obvious when you have someone go 20-3 and completely carry the match for their team.
But if you have smurfs running rampant in the lower tiers, intentionally duoing, or even some Diamond who wants to feel better about himself and jumping on his smurf to wreck people.... this is unfair. Now I have to beat a Diamond player just to enter Gold?
Be honest. The whole thing is stupid and should, in THEORY, have been disallowed a long, long time ago.
I don't even care if the queue times increase. I usually just browse YouTube or the internet while waiting for matchmaking anyway.
EDIT -
Literally, the first game I go play after I make this thread. Several smurfs in the game. The Lee Sin is self admittedly Platinum, smurfing in Silver to boost his friend.
Ranked is all kinds of broken.