A big part of the problem is over-generalization. Here's a reddit comment I posted in a similar discussion not too long ago, touching on that:
https://www.reddit.com/r/Python/comments/3nfbkr/patreon_is_a...
The person I was replying to there had made the mistake of assuming that because in these fields of programming, knowledge of data structures, algorithms and big-O characteristics is one of the most important things for performance, that must be true of all fields. When, in fact, it's not true of all fields, and I provided an example of one where it isn't true and where quizzing someone on their big-O cheat sheet wouldn't actually reveal whether the candidate has the most relevant knowledge for what's going on.