Apparently there is a whole host of reasons why you don't actually ever want to offer a bounty:
- You get -50 reputation even if you don't get a proper answer.
- You can't accept an answer after the bounty expired.
- Your accept rate (the percentage) is permanently reduced because you can't accept an answer.
Taken together, these factors mean that I will never ever offer a bounty again. But I'm annoyed because now there is a question with no accepted answer which brings my accept rate down for the rest of existence, and I had no way of knowing that beforehand. This is stupid.