We do this to allow people a "second chance." That's all they get, though, is to come back once (and maybe we've allowed one or two members more than once, but it's been the rare exception).

Some people simply have different comfort levels with an online community like this, and each time they come back, they want to start fresh with no pre-conceptions.

This is a rarely-used option, and it's rarer still where it's been done more than once. The community support team, of course, keeps an eye on returning members who change their username, to ensure they are here to give or get emotional support -- the same reason everyone is here.

Best,
DocJohn