You’re correct in that there are some companies out there using hacksathons to benchmark and also steal IP (I’ve seen some where the participants are required to sign a document saying said company owned all intellectual property produced during the hacathon - hidden in small print)

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