Hello org-mode team !
I get the feature that make me so sad. 
so I have settings.org file like this:

=====
 #+BEGIN_SRC elisp
      (setq mac-command-modifier 'meta)  
  #+END_SRC

 #+BEGIN_SRC elisp
   (provide 'settings)
 #+END_SRC

#+PROPERTY:    header-args:elisp  :tangle ~/.emacs.d/elisp/settings.el
#+PROPERTY:    header-args        :results silent   :eval no-export   :comments org
#+OPTIONS:     num:nil toc:nil todo:nil tasks:nil tags:nil
#+OPTIONS:     skip:nil author:nil email:nil creator:nil timestamp:nil
#+INFOJS_OPT:  view:nil toc:nil ltoc:t mouse:underline buttons:0 path:http://orgmode.org/org-info.js
=====

=====
init.el - like this:
(mapc #'org-babel-load-file (directory-files dotfiles-dir t "\\.org$"))
=====

but in definition of the function org-babel-load-file in org.el in line 243:

==
223 (defun org-babel-load-file (file &optional compile)
243	    (car (last (org-babel-tangle-file file exported-file "emacs-lisp")))))
==

So, we have so hard definition "emacs-lisp”, 
it have not allow us the custom header-args like -> #+PROPERTY:    header-args:elisp  :tangle ~/.emacs.d/elisp/settings.el
I think, It’s good idea to make that more flexible. 

Thanking for fix it.