Why is an empty field on translated taxonomy term showing default language value?
You may get it to work by using the Internationalizations Views module, which extends the i18n module with multilingual support for Views.

To make Views results correspond to the language switcher, add a filter for Content Translation: User's Current Language, which is the language that an authenticated user has set in the user settings (it is NOT the same as the current browser language or the site language).

If no option for the User's Current Language is available in the filter criteria form, then verify your configuration at Configuration -> Languages -> detection and selection: The order should be URL, Default, User and not something like Default, URL, User (as mentioned also in https://www.drupal.org/node/1701854#comment-6279474).

Note: True, the Internationalizations Views module only has a DEV / Alfa version for D7, but right now there are over 37K users using this version. Therefor I think "DEV" is not a valid release qualifier for that version anymore, because +37K users can't be wrong, right?