Silly question about user documents

I am wondering.. Is there any reason why ALL user documents have to be in the XWiki space? Wouldn't it make more sense to have an XWikiUser space, and perhaps an XWikiGroup space? For those of us with large installs already, it would be a pain to move.. but it doesn't seem to me that auth code checking for users should care much about what space the user document is in (aside from authorization/access, I suppose, as that is based on the space), but still, I think separating user and group documents out into their own spaces would make navigation of the xwiki space easier... thoughts? -- Waste of a good apple. --Samwise Gamgee