We clarified it in our bounty issue that only the best-winning submissions would get the bounty. Other folks have chosen to award all PR submissions regardless of hiring outcome. The format is up to the company hiring.
You're making a great point! It's exactly about what we ask from people who don't get hired.
I think real-world coding, getting reviewed by the CTO / hiring manager and getting compensated beats standardized coding tests & imaginary take-home assignments any time of the day.