orderby:date not working

You should not have to specify orderby=date. That is the default. If you look at the query, you will see that the field used is post_date, which is the publication date and not the modification date– post_modified.

You can prove this just by dumping $wp_query after your call to query_posts. Or try:

$q = new WP_Query('posts_per_page=-1');
var_dump($q->request);

With no other parameters you get ORDER BY wp_posts.post_date DESC.

If you are not getting that order there is already a filter that is altering default behavior. What is adding that filter I can’t guess.

And yes, please don’t use query_posts.

It should be noted that using this to replace the main query on a page
can increase page loading times, in worst case scenarios more than
doubling the amount of work needed or more
. While easy to use, the
function is also prone to confusion and problems later on. See the
note further below on caveats for details.

http://codex.wordpress.org/Function_Reference/query_posts (emphasis mine)