Outside of our tag scoring, I think there's a more simple solution for not having those tags:
Events in the books are generally well-known enough that citing the specific book would be superfluous. Additionally, many of the questions may actually require answers that draw upon multiple instances of the work.
In general, our use of individual work tags is spotty (as in usual in our tag use):
- A Song of Ice and Fire has no individual work tags.
- Lord of the Rings has 3.
- Mistborn has 1 of 6.
- Ender's saga has at least 3, of 15 or so existing books.
- His Dark Materials only has 1 (and that one only has 1 question, even though it's also a movie!)
- Sword of Truth has 0 of 14+ tags (if you count the Richard and Kahlan novels, and Law of Nines, it goes up).
- The Chronicles of Narnia has 0 of 7, just narnia.
Granted, those last 5 have very few questions to begin with (a shame, in my opinion).
Having said that, I don't see any reason to remove individual work tags, if people start using them, with one caveat:
The question should be requesting answers that are contained within that book (or film) only. To me, it actually makes more sense with the films, as they are more self-contained than the books. (Note, this caveat is just my suggestion. I just don't see a reason to remove individual work tags in general. We should be creating tags, not destroying them.)