I think both things can be true. These are valuable skills in some situations/jobs and you're selecting for students with these concepts still fresh in their minds and/or people who enjoy algorithm competitions.

And that's fine! A specialized subset of engineers. Maybe that subset is exactly what you need.

I wonder how the stress of the interview process selects out people who understand O-notation and to whom a Trie would make sense if explained to them, vs people who have these concepts fresh in their minds and/or can handle themselves in stressful interview situations.