What does it mean to be dispassionate?

It does NOT necessarily mean being heartless, without compassion,or unable to experience any kind of feelings.Its usual use is to indicate that a person can observe and think about something without being affected or swayed by personal feelings or strong feelings of others. You can be compassionate as a person and still hear a story or observe some event dispassionately. You can have empathy for the participants and even feel their anguish to a limited extent, but you can hold back your own emotional response so that you can gather and share the accurate facts, or to make a needed decision about what happened. The Word is sometimes used to suggest that a person is devoid of passion but again, that is not the usual meaning of the Word. So for example you would want savvy and dispassionate people on a jury if you were on trial, and you would want to be able to act dispassionately if you are a reporter or if you have influence or control over others who are in very emotional settings or situations.

It is good to be able to be dispassionate when that is appropriate.