I think there is a lot of churn, but that's good as it continues to be a place that people learn, and share and get good advice. A person who wants to learn about commuting can pretty much get all the advice they'll ever need using the search function.
Like others who have been around for a while I tend to come and go a lot, peaks and valleys. I try to chime in if I think I have anything of value to add or find something interesting to share with others, and I enjoy reading the odd story or about the unique ride experiences and gear stories people share here. I'm gonna stick around for a while yet.