They're there because they heard they'll get a big salary they don't deserve at the end of those 4 years, not because they have any interest in the field or want to contribute anything to the world.
It's probably been like this since the dot-com era and the mediocrity has only snowballed since. The state of the software industry and the educational institutions around it is an embarrassment. If the curriculum was any good, these minimum-effort clowns would not be able to earn a degree in Computer Science.