This video sends an important message that I think every EBW should heed. When you complain about someone you may bias the listener against that person. This can be harmful to you if you are complaining about someone you care about (e.g., you boyfriend, husband, child, or friend) because then the listener may treat that person negatively or encourage you to distance yourself from them. In fact, if they insist you leave the person and you refuse that could hurt your relationship with the listener! Talking behind someone's back in a negative manner is never nice but of course people want to talk about their relationship problems in order to cope.
So I think that we have to do such things in moderation, try to not be entirely negative and show more balance, make note of your role in the conflicts, and be aware of the possible negative consequences of complaining. You don't want to become Negative Nancy who is always complaining but never doing anything to improve your situation. Furthermore, if you are speaking so negatively about someone you care about the listener may wonder if you are not doing the same thing behind their back!