How to edit/override/theme the vocabulary views of the Taxonomy.module ?

I've been trying to have a customized view of my vocabularies (well, just one in particular but I would cope if it be the same theme set for all of them). That is something modules won't do well enough for me now (buggy and not maintained, unconvenient design, etc. I tried a lot of them.)

Thus, trying to theme my specific vocabulary with views, I couldn't manage it. I've been surprised to find out that the taxonomy view customization feature existed only for terms (admin/build/views/add/taxonomy_term) and not for vocabularies. Yet, two views exist for vocabularies: the default view of all vocabularies, and the specific vocabulary view:
- taxonomy/vocabulary
- taxonomy/vocabulary/vid
While views is clearly used to display them, none of them is given as a default view in the views administration page (admin/build/views). Therefore, none of the two vocabulary views is offered to customization (overriding the default view)...

Is there a reason for that?

I wish there was a taxonomy.module project/issue page to adress this...
... 'cause I feel like sending a message in a bottle...

Note: I've search in the drupal.org content for:

- "edit vocabulary view"
- "override vocabulary view"
- "theme vocabulary view"

with no success, not a single relevant topic. Any help?