Having people on your friends list makes it easier to see if their online thru the quick links, contacts popup in the event you need to send them a pm to ask a question or talk about stuff in private.
I don't use it like folks would use Facebook the more the merrier.
I don't see issue's with folks not having any friends on their list it doesn't make you any less friendly since your judged on what you post and not HOW many friends you have.
