There are several reasons to disable tags inheritance. For example, in project management there could be a tag for a direct responsible for a task, and a different tag for a different direct responsible for a subtask. I could want to see the tasks of the direct responsible, not the subtasks that are already in the hands of a different person. It helps to not overpopulate results.
Other use cases, like people that use :prj: tag for projects, subtasks could be not projects: http://juanreyero.com/article/emacs/org-teams.html Packages must exist that have functionalities based on tasks inheritance: https://github.com/gizmomogwai/org-tagged/issues/8
