The usage of a default tags vocabulary can be misleading to users. Having one example vocabulary can give users the option that the module is limited to only that.
Possible Solution:
Have both a tags and categories vocabulary as sample content. This would help users understand that taxonomy is capable of categorizing things in many different ways.
Comments
Comment #1
andypostThis vocabulary is always empty for tags because #762604: Taxonomy terms list broken, term add/edit forgets it's parent
Comment #2
sunI don't think that is a problem. This thinking would imply that there also can only be one user role (authenticated users) and two content types (the default) and so on... illogical.