Therapeutic rants is probably a euphemism for "bitching" amongst many circles, but what I mean when I myself rant about the topic is the idea that we as humans relish being heard and understood. The idea in my mind is that humans all have varying forms of expression which is a necessary component of psychological survival, much to the same importance as the physiological requirements of food, water and shelter. Some people also like to use the term debriefing, gossiping, catching-up, diary writing or praying.