Why do people who consider themselves good communicators often fail to actually hear each other?

To someone who prefers to vent, someone who prefers to explain seems patronizing; explainers experience those who vent as volatile.

This is why so many of us see our conversational counter parts as lecturing, belaboring, talking down to us, or even shaming us (if we vent and they explain) or as invasive, out of control, and overly emotional (if we explain and they vent).