Trying to write custom handler to extend views_handler_field_term_node_tid
You must adjust your module's weight so that it runs after views. Use hook_module_implements_alter or Modules weight

And then you can also change your code in MYMODULE.views.inc to something simpler:

function MYMODULE_views_data_alter(&amp;$data) {
  $data['node']['term_node_tid']['field']['handler'] = 'MYMODULE_handler_field_term_node_tid';
}