A Question for those who use Chat

So I am an experienced online chatter who has never had a problem being on cam and have always taken the etiquette that its better to chat in the room and not pester females or anyone else by private messaging if I've not chatted in public first. However I've noticed there are loads of people who come to chat and don't chat, what is that about? Or, am I missing something here and do I need to be more forward and start PMing people to chat?