It depends on the kind of hackathon you want. I agree that having prizes makes everything more competitive and serious, but it probably also increases the overa

It depends on the kind of hackathon you want. I agree that having prizes makes everything more competitive and serious, but it probably also increases the overall quality of participants. A new developer with maybe a couple weeks experience probably wouldn't bother with this hackathon but would try their hand at a hackathon that doesn't feel as competitive. Do you want the hackathon to attract a wide variety of people or do you want to target top quality engineers? There's no right answer, it's up the organizers. YC has chosen to attract quality, which makes sense given their business goals. An organization that teaches people to code should focus on being inclusive and avoid the competitive nature of valuable prizes. To use your sport metaphor, professional sports are very competitive and attract amazing talent. But you or I would never show up to compete in a pro-sports game. We might join the game in the neighborhood park though.