Here's a chat log from a game I played yesterday: https://www.dotabuff.com/matches/7902208511/chat
Some wholesome banter and that's about it.
In fact most people in dota have maxed out behavior scores.
You have to try pretty hard to be muted in the game or have behavior or communication scores lowered significantly.
I can assure anyone that just because you're sitting at 12k doesn't mean your experience is going to be good or an "entirely different experience"
It could be more aggressive at lowering score tho, true. Used to be. They "buffed" the gain per 20 matches last December, but it was great before (And even lowered the scores of streamers that had it coming).