Does anybody have idea why this question does not order results by "start_date" custom area?

$events = new WP_query(array(
    'category_name' => 'events', 
    'posts_per_page' => 4, 
    'meta_key' => 'start_date', 
    'orderby' => 'meta_value', 
    'order' => 'ASC', 
    'meta_value' => date('Y-m-d'), 
    'meta_compare' => '>='
));

After I look what query it creates, it states ORDER BY wordpress_posts.menu_order, wordpress_posts.publish_date DESC rather than showing approaching occasions and ordering results by start_date climbing...

...what shall we be held doing wrong?

(oh, after i remove meta_value and meta_compare, still it does not sort... dates have been in "Y-m-d" format so that they should sort alphabetically... so I am from ideas)