So there are occasions where a new user wants to add a tag but lacks the rep. Two examples of this happening to me:
- I want to add a cornmeal tag to the cooking site.
- I want to add an XSD tag to the webapps site.
Now I could request via meta (which I guess I did) or even flag my own post for moderator attention, but I miss out on the taxonomist badge then. Finally, I feel that there are a lot of cases when new users would be generating good new tags. For example, I would expect that if a snobol programmer were to discover stackexchange, he would start asking snobol questions on SO, and mainframe questions on SF.
I do realize that adding new tags did not always require such high rep as I have earned the taxonomist badge on super user.