I don't know if I thought of it as unfair as much as self-defeating on the employer's part. In the specific case of that interview, I told them upfront that I was not an expert in the practice of AngularJS. I understand the concepts of Angular at a very high level, as evidenced by writing a competing framework with more advanced modules and superior algorithms.

Why they would then sit me down and ask me to code up a full site in a hour is beyond me. This is something I would think is a legit request of a candidate who came in saying they were an Angular expert. But why waste your time on person who has already told you they don't have that skill set?