why is logged_out.html not overriding in django registration?

The django.contrib.admin app also has a registration/logged_out.html template.

To ensure that the template from your 'account' app, is used, make sure it is above 'django.contrib.admin' in your INSTALLED_APPS setting.

INSTALLED_APPS = (
    'account',
    ...
    'django.contrib.admin',
    ...
)

The app template loader goes through the apps in INSTALLED_APPS, and each app's template directory until it finds a match. Therefore, if admin is above your app, then Django will use the template from the admin instead of from your app.

You can set to redirect it to a next page like this:

url(r'^accounts/logout/$',auth_views.logout, name='logout', 
                           {'next_page': '/path_to_your_page/'})

According to: https://docs.djangoproject.com/en/1.9/topics/auth/default/#django.contrib.auth.views.logout

Or

<a href="{% url 'logout' %}?next=/path_to_the_page"> Logout</a>