I think Hackathons are just a tool to take advantage of entrepreneurs. They make it seem fun but the reality is that the pressure and unpaid work that you do is a toxic combination.

Many hackathons don't result in the host taking possession of the work you do. If they do I concur with you

Hackathons can be exploitative, but they don't need to be. Seeing what people can come up with in a ridiculously small amount of time is very inspiring, and the competitive element pushes you to build the coolest thing in the shortest possible time.

Hackathons suck ass and generally elevate the host of the hackathon vs. any real meaningful help of the team formed post event.