Why doesn't WordPress set post_date_gmt on drafts?

When inserting draft posts, why does WordPress set post_date, but not post_date_gmt? I think if you have two columns in your database, one for representing local time (post_date) and one for GMT time (post_date_gmt), both should always be set/updated together for consistency.

This is from post.php:

if ( empty($post_date_gmt) || '0000-00-00 00:00:00' == $post_date_gmt ) {
	if ( !in_array( $post_status, array( 'draft', 'pending', 'auto-draft' ) ) )
		$post_date_gmt = get_gmt_from_date($post_date);
	else
		$post_date_gmt = '0000-00-00 00:00:00';
}