BTW the Membership Board has constructed an official policy on dealing with requests for membership after the membership has expired. This adds a little additional auditing piece in the event that someone’s not willing to keep clicking the renew button. I think that, to some degree, deals with at least part of this discussion.
That said, to add my 2¤ to the general discussion, I think it’s important to remember that this is Ubuntu and that means “humanity to others.” That said, if we have members of our community who are not contributing, we shouldn’t consider them former members. We don’t need to kick them out because they’re not proving themselves worthy.
What we may want to do is to try to figure out some way to engage with members who are not contributing very much. I know Launchpad Karma isn’t worth much, but having any Karma generally means that you’re doing something with the project. Wiki contributions are another thing to look at. We could collect a couple of these things and write some scripts to generate a list of folks not contributing and maybe it could be a thing the Membership Board could do to bring them back on. Not police, but more of offering a helping hand, inviting them back in.