I believe Java is chosen for its popularity and its static typing, which helps the learner gain a better understanding of the algorithm at play than a duck-type

I believe Java is chosen for its popularity and its static typing, which helps the learner gain a better understanding of the algorithm at play than a duck-typed language would. It is even better to learn algorithms in C, where one has to work directly with the memory trade-offs. But learning these algorithms in Java is certainly more effective than learning them in Python, Ruby, etc.