Earlier quoted context omitted.
Really agree with this. Not everything is about money, if it was we wouldn't have squid, postfix, apache, nodejs, python and the millions of other open source software that I and everyone else here relies on daily. Ask the maintainer of GnuPG if he was ever given $10K by a company (prior to the Linux Foundation's Core Infrastructure Initiative grant).
This is the distinction I was getting at - something like GnuPG provides tremendous value to society as a whole . Saving ArcelorMittal some money in its manufacturing process doesn't benefit anyone except ArcelorMittal's executives and stockholders. So I stand by my point. There's no doubt the participants got a lot out of this Hackathon, but I'd wager that ArcelorMittal got significantly more.
If the above assumption is true then I don't see the problem. ArcelorMittal get some buzz and maybe some ideas to pursue, the hackers get a fully paid fun weekend and a little cash for their efforts, society potentially benefits from the seeds that were planted.