What the point of EarPods?

Come back to University as a mature student for MSc and I did notice a new trends (?)

Fellow (young if I have to be specific) students come to class with EarPods in their ear and keep on using EarPods throughout the class. How can you listen to teacher lectures, been in seminars etc. All with EarPods in one of your ear.

Also those who did have EarPods on all the times why? You not having any headache or scare of ear infections?