Bernard, I think Shawn may be right.
I don't think there's evidence that a significant proportion of WT newcomers react to not having understood the WT philosophy by deleting, or trying to delete and disconnect, all the profiles they've added.
There are a few obvious cases of enraged newcomers who post to G2G about their disappointment with the site and try to delete what they've added. But several hundred people a day sign the Honor Code, and that is about a third of the total new members, who are still allowed to add limited family profiles. While some number of HC signers also leave WT each day, my impression, including from my own contacts, is that most of them simply lose interest.
It's not clear to me from the help page for closing accounts what happens to the deceased private profiles (living profiles with no other PM are deleted).
There are several ways that accounts get closed. Voluntarily, yet my guess is that most of those people don't leave in anger and don't try to delete their work. Involuntarily, due to years of inactivity and unresponsiveness to contacts about their profiles. Again, I doubt those people bother to delete their work. I think those two group make up the vast majority of people leaving WT. Then there are the very few intransigent, uncollaborative newcomers that get thrown off. I doubt that profile deletions based on those few members significantly affects WT statistics.
It is possible to review the contributions of new members by sampling recent Honor Code signers. Some people treat WT like a Facebook account, adding all their living relatives without ever adding any ancestors or connecting themselves to the main tree. I can't say what proportion of newcomers that is, but in the cases where they quit WT, all those profiles will be deleted without reducing the connectivity of the tree (in fact, those deletions will increase the connectivity).
Edit re my last point: That would increase connectivity only if the calculation had included unlisted profiles.
