I just created a bounty and I would required to select one of the following reasons:
- Authoritative reference needed
- Canonical answer required
- Current answer are outdated
- Draw attention
- Improve details
- Reward existing answer
How about "still looking for a correct answer"? Now, my thinking is probably biased by my current situation, but isn't that the main to ask a question in the first place?...because you are looking for an answer? Why shouldn't this also be an option for a bounty?