If a user doesn't want to configure, they won't. Configurability does not lessen the value of the desktop. Those clueless users that want only what everybody else has, and no more, they shouldn't be forced to configure. By all means, sane defaults!

But... being forced to do the equivalent of editing the registry to tweak (unless, as has been pointed out, you install some other package that makes it easy to configure but is not part of Gnome) does NOT ad value to the desktop. Making it a PITA to tweak isn't locking it down either (as should be possible, and I've said elsewhere) - it's just a PITA.