Reading through this thread you can see how many people on HN don't understand non-verbal communication (note anotheryou, this isn't directed at you, you seem to get it).
I do wonder if some of these people realize they may not be neurotypical, even if just slightly. A huge amount of human behaviors and communications are encoded how we move and how our face reacts. If for some reason you can't pick up on or interpret this, then human behavior can be quite confusing.
In some sense everything is communication but that's going too far for "talking". In the more normal sense finger drumming can be communication but 90+% of the time it's not.
I do wonder if some of these people realize they may not be neurotypical, even if just slightly. A huge amount of human behaviors and communications are encoded how we move and how our face reacts. If for some reason you can't pick up on or interpret this, then human behavior can be quite confusing.