Matchmaking

It is well known that you are not allowed to duo with someone who is either two or more divisions above or below from your own rank. So why is are players who are more or less than 2 divisions away awkwardly playing in games in which they don't belong? It ruins the game for most people because they are either hard stomped or forced to try and carry a player who goes 0/10+ and lacks the game knowledge and communication of their teammates. Of course the 'get good enough to carry everybody in every elo argument' is infallible, but this seems to be a common occurrence for me and my friends, so even though that argument is logical, it is not always practical for the average player. I am posting here in hopes that the developer team sees this and other posts like it and over time, see the need to inquire and see if these mismatched placements are as common as they feel for myself and those who I associate with.