Why is it compulsory to award a bounty to an answer? I'm in a situation in which a bounty of mine has received only one (incorrect) answer, an hour before the deadline. What I see is compatible with the answerer having bet on their rather rushed answer being the only one and thereby getting the bounty. Awarding it encourages questionable behavior in cases such as this.
I understand that we obviously don't want users to set up a bounty in order to get good answers only to withdraw it later. A solution could be to lose the bounty anyway if you decide to make it vacant. This would disincentivize set-up-then-withdraw behavior.
An I missing something about how bounties work?