I could be wrong but that's just how I feel about it.
Lastly, if I were to organize a hackathon. I think the the first I would do would be making it at least a week long instead of 2-3 days. In addition, I would make it required to not allow participants to stay more than 8 hours each day. After all when I think of hackathons, I think it's a time to tinker with technology and come up with something cool. NOT staying up for 3 days straight to win some prize.
It’s disgusting behaviour because a hackathon is supposed to be about freedom of ideas, intellectual stimulation and humour and fun - and these companies are just purely exploiting it. They should be named and shamed.
I would add that any halfway decent manager understands that while a developer can sprint, it is by definition an exhausting short term gain, and this is an unsustainable medium and long term strategy : and if your manager doesn’t understand something so basic about people management, it’s time to look for a new job
The downside of week-long events is that you exclude people who have to go to work or have other commitments, but might be able to make time over a weekend.
In game design circles the equivalent of a hackathon is called a game jam. They are almost universal and are seen as an excellent opportunity to both try out ideas and socialise with other people that you wouldn't normally get an opportunity to work with.
> Almost everyone that attends says they are exhausted by the end [...]
Same is true of the gym. That's not an argument against.
> [...] you tend to consume unhealthy food & beverages in the process.
That's a function of planning. When we run such events we provide healthy food (fruit, primarily) for free. But we also have pizza, as we do at all of our other social events. That is more of a function of group events than of hackathons per se.
I think your concern for the well-being of hackathon participants is admirable, and if you ran such an event I think you would do it very well. Have you considered organising something?