AFAIK, only moderators can delete a tag. In that case, how do we notify the moderators for unwanted/useless tags? Eg: mountain-identifying is a tag.
It also states that
If the tag has 0 question associated with it, do not submit a tag deletion request. Tags with no questions under them are automatically deleted by the system within 24 hours and no action on the moderator's part is required.
which implies, re-tagging the single question in this post will remove it.
All it takes to delete a tag is to remove it from all questions and then it will be automatically deleted. In the case of tags with lots of answers, it makes sense to ask on meta before retagging while if there are only one or two then one user can quickly delete it without boring everyone else to death.
The only time a moderator is needed to delete is when we are switching out tags. Changing rope to ropes would require a regular user to remove it from all questions, wait 24 hours and then put ropes back onto those questions. Changing uk to united-kingdom would require retagging of all of the questions tagged with uk.
In both of those cases, it would be better for a moderator to use their tools and avoid the retagging.