I actually don't have a problem with the data structures interview exam inherently, my problem is with how it's administered.
It doesn't bother actuaries have to take exams to demonstrate an understanding of linear algebra, vector calculus, stats, numerical analysis, and so forth. Nor does it bother me that they have take these exams even if they took the material from a reputable college with a good grade. I think it's great that the actuarial field will allow people from multiple educational paths to take the test, giving them a choice about how they learned the material.
But here's the thing - software developers have to take these "interview" exams over and over, at the whiteboard, every time we look for new job. And unlike the actuarial exams, we take these tests under conditions of tremendous secrecy. We don't know if our examiners are qualified, or if their questions are vetted, or if the exam is consistently applied and graded. We don't have a clear and defined study path, aside from books like "cracking the coding interview". And we get no feedback, hell, at times we don't know if our performance was evaluated at all.
I've considered this for a while, and I've come to understand that exam-based professions and institutions, such as the medical boards, the bar, universities, have evolved a set of considerations, kind of a student bill of rights. Students must submit to the exams, but they have the right to a fair and consistently administered exam, evaluated by respected people in the profession or field, that the exam questions should not be capricious or utterly unexpected, that there is a preparation path, they get feedback on why they did not pass. What we have in tech is the stress and burden for examinees, in many ways amplified (whiteboard coding, on the spot, is among the more stressful ways to take an exam). But the student bill of rights is largely non-existent, and I think this is the deep and severe problem with tech interviews. Until this changes, to me, nothing can change meaningfully. And I don't just mean in interviews, I think this sort of thing is what is deeply rotten about tech, at the core of many of the problems (in a field where there's a lot of suspicion about bias, are secret tests under capricious conditions a good idea?)
And we're expected to come back for more of this, over and over, and to just take it.
Oh, by the way, there's a shortage of software engineers, best solved by putting tech companies in charge of the immigration system so they can decide who is and isn't allowed to come to the US based on how well they do on these interview tests/how much they're willing to put up with these interview tests.