I think it's all about speed. In "real life" everything can be looked up, but exam optimizes to not even having to look it up. Then any research becomes much faster.

Whether it's good or bad I don't know, I think US higher education focuses too much on ability to produce huge amounts of mediocre work, but that's the idea behind exams.

One of the reasons I've always encouraged software people to learn to touch type has nothing to do with typing speed - it's about reducing/eliminating the cognitive load of typing, you want to be thinking in expressions (sentences) not letters. (The increase in effectiveness comes from not getting distracted by the mechanics of typing...)