At Caltech, most exams were take home with a time limit of 2 hours. Some were "infinite time". The students hated the latter, because it means there was no end to the time you needed to spend on the exam, meanwhile there were other exams, etc., to take.
With a 2 hour exam, there's an end to it, and you know how much time it should take to do the problems. Much better.
It's even worse if you're being graded on a curve, as you would be in a job interview. You're competing against others who will spend infinite time on it.
Like you said, "there were other exams, etc., to take.". Presumably other competitors have other exams as well? You'll thus be competing against people with different time management skills.
With a 2 hour exam, there's an end to it, and you know how much time it should take to do the problems. Much better.
It's even worse if you're being graded on a curve, as you would be in a job interview. You're competing against others who will spend infinite time on it.