Every Facebook group on the planet has that one person who never shuts up. A group member could post something that has literally nothing to do with them, their family, their interests, or their expertise, and they will still find a way to comment about it. I know a lot of people who love to hear the sound of their own voice (myself included), but I can’t imagine the appeal of the sound of yourself typing. 

For some, posting behavior like this is a sign of loneliness. They want to be a part of every conversation happening online because they don’t have anyone to talk to in real life. For others, they really honestly believe that their perspective is essential on every topic no matter how irrelevant. It must be extremely fun to live inside their heads, even if it isn’t the most realistic, helpful, or intelligent mindset to have.