WP_Query can’t exclude more than 1 author?

It seem wp_query have the problem where it does not accept more than 1 negative value in author argument. for example:

$args = array('author=-2,-3,-4'); 
$newquery = WP_Query($args); 

This grab everything else. Simply doesn’t work.

I found this trac, but seem still no official patch for this.

Any suggestion?

You are right, it is not possible to pass an array with author IDs to exclude them. The reason is in wp-includes/query.php at line 2294 – 2298

if ( strpos($q['author'], '-') !== false ) {
  $eq = '!=';
  $andor="AND";
  $q['author'] = explode('-', $q['author']);
  $q['author'] = (string)absint($q['author'][1]); // this line select the first ID and only this ID
} else {
  $eq = '=';
  $andor="OR";
  }

You have to get all author IDs, then exclude the unwanted authors and request the posts from the remaining authors

// array for user IDs
$users   = array();

// roles to include
$roles   = array( 'author', 'editor', 'contributor', 'administrator', 'superadmin' );

// user IDs to exclude
$exclude = array( 2,3,5 );

// get all users
$_users = get_users();

foreach ( $_users as $user ) {

    // do not add the user ID if the users role does not match or the users ID is excluded
    if ( in_array( $user->ID, $exclude ) || ! in_array( $user->roles[0], $roles ) )
        continue;

    // add user
    array_push( $users, $user->ID );

}

$args = array('author=" . implode( ",', $users ); 
$newquery = WP_Query( $args );