Hubpages is a place where you hang out with a bunch of nice people who want to share their beautiful words and knowledge with you and hope that you'll share back. If those are the characteristics of an addiction then hanging out with my friends at school every day is an addiction. Hubpages is a kind community.
Addictions are harmful, so yes, if you neglect your pets, children, or spouse for hubpages it would be an addiction, however I don't think that this is the case. I think hubpages is more of a casual community, it's not like gaming or gambling websites where every moment is spent trying to be the best and beat your competition. At hubpages the goal is to work together and create beautiful, useful content.