Actually, Sherry, you and Kelli both "unjoined" the cubit back in February 2012, but some others joined just in the last couple of years, though it's hard to figure out why they would. No one has posted there since 2012.
There's not much reason to keep it alive except for those drop-ins. If an average of 65 people dropped in every day last month, they had to have been drawn by something, most likely a Google search for one of the nurseries, the See's fudge recipe, or something else. They aren't joining in the conversations because it's clear from the posting dates that no one's there anymore, but we can't assume that they aren't into gardening. The threads related to gardening aren't there anymore, so they can't join those conversations unless they move from Cubits to ATP.