Same, and seeing companies puting devs in charge of interviewing ops people makes the game even worse.

Those concepts arent that hard though. Just spend a day and familiarize your self with it. The most important take away from those kinds of questions are, can you pick the right data structure when you need to. Using a list vs a hash map, and will you avoid doing things like nested for loops. Big O just puts into words why you want to avoid those things. Most of the concepts should be intuitive already if you have some experience. Personally I haven't seen an interview go in deeper then that.

If your writing a script that will touch 10k servers, the operation is likely already slow. if you throw an unnecessary for loop that iterates over everything and runs something, that's going to a painfully slow script and wasteful.

Big O is kind of a valid question for ops in terms of response time versus load.