I don't see any value in deleting members who haven't posted or visited in a certain amount of time. Who cares if we have 13k members but only ~2k active ones? I wish I could go through and delete all of the obvious SPAM accounts that signed up, but I don't have the time for it. Other than that, if you register, you'll always be a member unless you're banned. I didn't see any compelling reasons posted as to why we would want to delete these inactive members, and I've never heard of any other forum doing something like that.