I find it interesting (not in an encouraging way) that answers start to show up only after the 7 day period expires. The bounty system works by awarding the bounty points to the oldest answer or the answer that has the most upvotes. Plus at least one answer will get some points. This means an answer will get a big chunk of points no matter what.
I would like to believe that people genuinely want to help and are not just posting weak non genuine answers just because there's a high chance to get some easy points.
an answer will get a big chunk of points no matter what
- That's not strictly true. Only answers with a score of at least 2 are eligible to receive an auto-awarded bounty (half value). If there are no such answers when it expires (and after the "grace period") then the offered rep is simply lost.