I 'member from last year that someone said that "the staff worked their butts off, so they deserve something more special", but their hard work on the site doesn't justify why the avatar height extension is limited to the staff.
When I read that the extensions were disabled because "it would make the pages stretch", I actually did research on that. So basically speaking, the avatar height extension was made "staff-only" probably for the same reason why signatures have a maximum height of 250 pixels.