I’ve encountered a lot of players who are stuck in a specific elo. I think part of this is due to the crowd there involved with … is ultimately players of similar elo who make the same arguably poor strategic choices. Before games had matchmaking, take for example your standard FPS, you’d join a server which would contain a good sample distribution of players at various skill levels. So you’d be consistently exposed to arguably significantly higher levels of strategic play and more precisely, the collision of various levels of game play giving you firsthand experience why and when various tactics work. This discrepancy between the skill level of players in a server, I always felt, was a good influence on players to not only constantly improve themselves but also clearly showed them moves or strategies they could try to do so.
With matchmaking though, you do not get this kind of exposure because you are placed with players who are very near to the same skill level. Now obviously there are strong merits and reasons behind this. Such as, in League, a very team-performance-dependent game, it’s extremely aggravating for higher-level players to, for-lack-of-a-better-term, be weighed down upon by the novice choices of less experienced players. Furthermore, those that play for the challenge will not find it if they are consistently far beyond the skill levels of the peers they are matched with.
On the other hand, while I have no evidence but experience to support this, match making, from my experience, creates isolated environments in which specific styles of game play are allowed to run rampant because they are rarely checked by their higher-elo-counter-play. For example, in Counter-Strike*, the infamous five man P90 rush, arguably does not have effective counter play with low skilled players. However not too far up the skill chain, a couple of well-placed counter-flashes, grenades, and well-aimed shots will always, utterly, decimate the aforementioned P90 rush.
Now, if you get a large group of lower skilled players and never expose them to such higher level play, eventually the P90 rush becomes the standard of play (along with all the bad habits). Soon anything but the P90 rush (i.e., off meta, or even higher level play), is meet with animosity. Especially in game such as League where victory is so dependent upon the performance and actions of your teammates (unlike CS* where a single skilled player can still clutch rounds, in League it’s very hard for a single player to carry a game, especially when their teammates continuously make bad decisions) the blame game starts and things go downhill all too quickly.
You could argue that the seemingly lack of counter play for a specific tactic alone, may provide enough inspiration for players to improve and as a whole, eventually we’d see the emergence of a counter-play directly from their isolated skill level. You may be right. In CS* this definitely can happen and is facilitated by the fact that you’d could easily play many rounds and even maps with the same players and eventually, as a group, learn, experiment, and invent such counter-play without being directly exposed to it. However, in League, this possibility seems to be crushed by the fact that it’s extremely rare to ever play more than one game with the same teammates inadvertently, not to mention that a lot is already decided at champ select.
Within matchmaking, the only real way you can improve yourself (even with first-hand exposure to significantly higher-play), especially after bad habits form, is with serious dedication to improving, by doing intense self-reflection, examining your game play and the games of those more experienced, etc. Without such dedication, it’s obvious and evident that players reach a plateau where-upon they get stuck. Getting stuck alone, seems to be a problem, let alone problems that subsequently follow… What happens when they get stuck seems to vary, maybe they become bitter and start down the road of becoming toxic (not to say this is the only way to become toxic, obviously not), maybe they get bored and quit, or maybe they make another account in hopes to get placed out of the slippery slope they are in… Even if they are having fun in the short-term, getting stuck is not very alluring for the long term.