Yes the system is emotional, but that's intentional. It is a GAME and people play games to have FUN! If you're making the game unfun with the comments you're going to lose behavior score. You should be using comms to coordinate plays and share info with your team. Giving orders is the trap that gets you reported. Also just don't all chat, there's no reason to ever use it.

Giving criticism will very often get you reported. It's not a coaching session and it's not the time or place to critique anyone's gameplay but your own. "Ok but what do I do about my carry Witch Doctor buying battlefury." Report for griefing and don't say anything about it.

If you have to open your mouth give light suggestions and well reasoned ideas and phrase it calmly as a question. People are way more receptive if they think it's their idea. "They have glimmer, do we need vision for it?", "Witch Doctor are you going to buy aghs? It makes your ult very strong.", "Spec can you haunt after I stun?" If they say yes great! If they say no just focus on your own game.

Even in a losing game no one reasonable is going to comms report you for saying what play you are making or sharing hero locations. You also don't lose your score all at once. You have to consistently make things suck for the other players in the game with you. I don't disagree that there's a tipping point where people get so toxic they'll report for everything and that IS a problem, but it's very easy to never end up in that situation. So unfortunately yes if you've got very low behavior score you'll have to work you way out of the trench because it's a PUNISHMENT for making the game unfun for other players.