While I don't claim to have the answer to your question, I think there's a jump you're making that may not be so straightforward and somewhat explain things. Y

While I don't claim to have the answer to your question, I think there's a jump you're making that may not be so straightforward and somewhat explain things. You say "people on HN seems to enjoy this kind of articles" which seems reasonable, given the comments here. But then you jump to "we think knowing theory is useful in cracking hard problems". Going from the first to the second is not quite so clear. That is, someone may enjoy such an article and even learning some theory, but not necessarily because they think they will directly apply it. People sometimes just enjoy learning stuff or reading about it and then forgetting it. You also make a second jump, because other factors may be involved. Maybe the theory asked in the interviews is completely unrelated to the things involved in the job. The job may not even require cracking hard problems. These are frequent occurrences -in my experience, at least-, and clearly seem compatible with thinking that knowing theory is good in general.