It’s a very good point that theory is very relevant to practice in software, regardless of what industry says or wants. It’s part of why I tend to look askance at people who claim that self-teaching is as good as a degree program for software engineering: the CS theory a good degree gives you is essential (necessary, though certainly not sufficient) to be a great programmer, and only the tiniest fraction of people have the attention and self-discipline needed to self-study it.
I do kind of disagree with the author’s generalization about hackathons: there are obviously plenty of commercial, “sold-out” events, but there’s plenty that aren’t, as well. The fundamental motivation for most participants is that programming is fun (or it ought to be), as is hanging out with like-minded and -talented people. There’s nothing wrong with this motivation, and it meshes nicely with academia.