Why Bother?

I find myself constantly asking myself this question in respect to those people who go to University who [think] they already know everything thing. Im sitting in my media/tech/poli class and the prof is talking about the loss of rhetoric and metaphor in our society. The question posed to the class was along the lines of this "Is the impoverishment of today;s language affected by technology?" The question was based around the idea that language has lost some of its effect and how does that affect things like mass media, and public understanding. Instead, there were several girls in the class who felt the need to attack the use of the word impoverished - stating that language changes - whether it is for the better of for the worse should be irrelevant... that from a linguistic persperspective, language use is contextual, therefore any historical debate is arbitrary (thats my interpretation of what they were saying) From them, it came out more like "You cant say that language is impoverished - I'm a well read linguist and therefore you cant really argue with me..."

I think to myself, well, the point of the original debate has been missed... AND these girls have the nerve to tell the professor that he is wrong, and that he shouldnt disagree with them??? I find myself asking why do these people bother attending university if they already know everything? Can't somebody just give them a piece of paper stating they're too freaking smart!?! At least it would get them out of my classes... Sadly, we didnt have much time to get to the actual [relevant] point of the topic at hand..
And so, i lost another 3 hours of education to people who think they know it all../sigh