I never understood the fascination with asking an applicant about minutia of data structures and algorithms. Isn't that the domain of reference material?
I gain much more insight into a person by asking them to describe a large system they've designed, what choices they made, the effects those choices had, ect. How did their initial assumptions hold up through the course of the project? How did they adapt to changing requirements? These are the things you can't find the answer to in 30 seconds on stack overflow.
Put yourselves in the shoes of an employer. There are a hundred candidates applying to your position. Would the answer of "just trust me" convince you to hire one person above the 99 other applicants? If only one of those 100 applicants showed they had the skills you wanted, right out of the box, wouldn't you feel better about hiring him?
I think the attitude of "they should hire me, since I can learn anything" is self-centered. There are a lot more people that can't learn. Without testing methods available there is no way to distinguish the self-starters from the frauds.
The problem is that most companies make terrible decisions about which skills they want right out of the box. They can't get people that are 100% on everything they actually need (as such people are unhireable for the job/pay they're offering), so they settle for people who know a lot about B+ trees (or more likely, how to reverse a linked list and do a bad version of quicksort on a whiteboard) because that's what the folks who have been studying their "how to get hired at a tech company" webpage know.
I get your point, but knowing the differences between http, udp and tcp isn't minutia ... it's cornerstone knowledge for anyone working with distributed systems.
I gain much more insight into a person by asking them to describe a large system they've designed, what choices they made, the effects those choices had, ect. How did their initial assumptions hold up through the course of the project? How did they adapt to changing requirements? These are the things you can't find the answer to in 30 seconds on stack overflow.