Really all you need to do is get better, or just play with 5's. You'll find that if you're actually playing with competent folks the arguments are generally cogent; albiet a little hostile. At the lower tier matchmaking you get to deal with all sorts of unwelcoming teammates who are frustrated and still learning.

I have a tough time agreeing with the opinion that developers and gaming communities have a moral obligation to take it upon themselves to enforce some code of conduct policy. Policing people's speech is a slippery slope, especially when the fundamental tool (the grand 'ole mute button) already exists to appease those that feel violated. Multiplayer games that are inherently competitive bring inherently competitive people to them. These types of people generally don't enjoy losing and if you're the cause of that, they'll probably let you know.

I'd rather have someone angrily yell at me in an attempt to correct my play-style than me mope in my private chat channel during a game because some algorithm labeled all my teammates as "Toxic Meanies". If what they're spewing in nonsensical garbage, then you mute them; this all seems very melodramatic to try and blow it into the proportion that I think you're attempting to get at.