WordPress, when will you fix this one-to-one relationship? It's ugly n I hate it

You can find this code below inside “content-gallery.php” (twentyeleven theme)

<?php
$images = get_children( array(  'post_parent' => $post->ID,
				'post_type' => 'attachment',
				'post_mime_type' => 'image',
				'orderby' => 'menu_order',
				'order' => 'ASC',
				'numberposts' => 999 ) );

if ( $images ) :
	$total_images = count( $images );
	$image = array_shift( $images );
	$image_img_tag = wp_get_attachment_image( $image->ID, 'thumbnail' );
?>

The problem here is:
1. When a post is a gallery post, that post will show a gallery of images.

The question is: How do i display an image inside that gallery?
The answer is very ugly: You upload your image by using the media button when you’re editing your post. That way, that image will be a child of that post. UGLY!!!

Why? Because this is a one-to-one relationship which means you can only use that image for ONE GALLERY ONLY! What do i need to do to use that image for another gallery? You upload another copy of that image.

WordPress, please fix this one-to-one relationship. It’s ugly