Have you ever worked in a place where some very serious bad sh--- is going down and has to be dealt with? My first career was in mental health work--psychiatric hospitals, community clinics, and also a stint doing child abuse evaluations in children's hospital emergency room. Terrible, awful stuff. Do you think as staff we didn't choose to keep those discussions to one place, and then talk about sports, films, weekend plans, etc. in another place?
Even in my second career, in a calm, non-stress profession, our Friday afternoon gathering for beers had only one rule: no work talk. It really is possible to separate where and when we choose to talk about things.