Something is definitely off in the low MMR trenches and reporting when you already have a low MMR score

This often leads to a cancerous loop of toxic/low MMR teammates reporting you for no valid reason really (in OP's example he was even supporting, which I never do) which ends you up in LP and lowers your communication score even further.

As soon as you get out of LP you are paired with the same teammates again, which are gonna report you again, rinse and repeat.

The system basically is not fair and does not work for people if they have the right combination of low MMR / low behaviour score. In 5k MMR this works because everyone at that MMR understands how to play so people can't pretend and say "im noob." In 3k this works because no one knows how to play so they report people playing badly or not playing according to their "gameplan" (which may not be a good gameplan actually, just a gameplan they are used too in 3k)

Essentially you'll have to conform and play their "3k strategy" (which is awful) or face reports and get LPQ. You can't argue with them as they will flame you, and them flaming you will create a lynch effect with other toxic teammates joining in to lynch you and report as well.

It's weird, but at MMR/BScore like this, the purpose of the reporting system gets turned upside down. Essentially, the reporting system is used as a tool to gain "vindication" or "scapegoat" someone after a lost game. This is preceded by unhealthy amounts of flame(routinely had to mute 1-2 persons each game cause they were being so toxic. Didn't talk back, didn't flame, still got LP) so as to get other people join in on the lynch effect and get them report you.

In this MMR, logic or arguments don't exist. Simply the ones who yell loudest or flame hardest typically get the most amount of teammates on their side, with the "victim" typically receiving LP.

There are of course arguments to be said, why is this person's Behaviour Score so low? Well I don't know, maybe he flamed and maybe he is trying to improve. But it doesn't change the fact that if you get so "low" in the system, it becomes nearly impossible to get out because of the chronic flamers and reporters. (and I can tell you it is a really unhealthy atmosphere to live in)

You've highlighted the problem. But what can be done to improve the system?

Because at low MMR / BScore combo people report you for asinine reasons or to simply find some sort of vindication over a lost game, the best solution I think is to simply lower the weight your reports have the lower your BScore is. People who are chronically toxic shouldn't be given as much weight on their reports.

So ideally, at low behaviour score, your reports would be worth 5x less than reports at someone with perfect behavior score.

The graph doesn't have to be linear, it could be moderate until you reach halfway then quickly take a turn as you dive towards the deep-end.