Let's attempt an analogy to bring these worlds together. You need an algorithm to process some specific data faster than any generic off-the-shelf algorithm can. Something like this: [1]. You post the results to HN, explaining exactly what you came up with as a result of 10 years of experience and 2 days of solid thinking on the subject. It actually turned out to be possible in relatively little code. You haven't implemented it yet, but intend to.
11 hours later, someone has already implemented and open sourced it. People argue you aren't being ripped off: after all, if someone can do that in so little time, "you haven't really invented or created anything (substantive)".
I would disagree with such an appraisal: it's your experience that made it possible for you to come up with this solution. That someone can implement it in a couple of hours once explained, does not reduce the value of the solution. You could probably charge an employer $10K for this expert solution, independent of how long it took you to come up with it. It's the same with expert designs. Once they are shown to you, they are obvious. It's coming up with them, and fine-tuning them, that's the hard part.
Now I'm not arguing that this is instance of expert design (I wouldn't recognize it if I were slapped with it) and I'm not arguing anything about this specific case (and I specifically do not think it is relevant to argue about whether you lose rights by publishing a design/solution). I'm merely arguing that the general argument that gets thrown around here just seems wrong and insufficiently appreciative of how hard it is to properly design something.