Because something went wrong? You can come over to http://localizer.norganna.org/index.php and help with translation. Login credentials should be the same as forum ones.
If we don't have a translation for a string, we display the enUS instead. Plus, some items may not have been added to localizer for translation (yet) - I know smelting was recently added by a new developer, so that may be the case for that tool.
Having said that, some of what you linked probably should be getting translated, not sure what's going on there. can you try redownloading the latest version?
you will actually have to sign up for a separate localizer account, I believe.