merge uid1 stylesheet into main stylesheet?

Admin menu has a 2nd stylesheet which contains only this:

/**
 * @file
 * Administration menu color override for uid1.
 */

#admin-menu li.admin-menu-account > a {
  background: #911 url(images/bkg-red.png) bottom left repeat-x;
}

Is there a specific reason this is a separate stylesheet which escapes me? Because it seems really odd to be to have a separate stylesheet for just this -- to me it seems more sensible to add a class to the admin menu output, and have a rule in the main stylesheet that selects back on that, eg '#admin-menu.admin-menu-uid1 li.admin-menu-account > a'. Am I missing something?