Calculate and display number of views in Genesis post meta

functions.php

//* Get post view counts
function getPostViews($postID){
    $count_key = 'post_views_count';
    $count = get_post_meta($postID, $count_key, true);
    if($count==''){
        delete_post_meta($postID, $count_key);
        add_post_meta($postID, $count_key, '0');
        return "0 Views";
    }
    return $count.' Views';
}
function setPostViews($postID) {
    $count_key = 'post_views_count';
    $count = get_post_meta($postID, $count_key, true);
    if($count==''){
        $count = 0;
        delete_post_meta($postID, $count_key);
        add_post_meta($postID, $count_key, '0');
    }else{
        $count++;
        update_post_meta($postID, $count_key, $count);
    }
}

//* Prevent prefetching from adding extra views
remove_action( 'wp_head', 'adjacent_posts_rel_link_wp_head', 10, 0); 

add_action( 'genesis_loop', 'nabm_get_individual_post_count');
function nabm_get_individual_post_count() {
	if ( is_single() ) {
	setPostViews(get_the_ID());
	}
}

//* Add shortcode to display counts in post meta
function nabm_post_views_shortcode() {
	echo getPostViews(get_the_ID());
}
add_shortcode( 'post_views', 'nabm_post_views_shortcode' );

@nutsandbolts
Hi
I found your code is useful for my work. I try to calculate most popular posts and pages in my plugin. But I have two questions:

1. why did you use delete_post_meta before adding post meta? If $count value is null, so there is no existing post meta for post_views_count, isn't it?

2. Why did you remove the action 'adjacent_posts_rel_link_wp_head'? please explain it.

Thanks