It's true. A few years ago, as a Political Science major I took a course called Politics and the Media. I expected an intellectually stimulating environment in which we would be presented with diverse ideas and be able to logically challenge them with intelligent discussion and debate... at least that's what I thought college was supposed to be about because that is how it was always presented in the old sci-fi novels I read growing up.
Ha! How wrong I was!
The teacher stated that, "There is no bias in the media" and called for discussion. Little did I know at the time, he was actually calling for blind agreement! I, being the naive individual for following my mom's early teachings to "question authority" and "challenge things that aren't right," proceeded to give examples of bias in the media. I was yelled at for presenting a dissenting opinion! Every paper I wrote from then on out was marked at least a letter grade lower than could have ever been justified by the most harsh critic.
This became most obvious when I was given half-credit for an extra credit assignment. When I asked why, he said I was lucky I got any credit. A nearby jock acquaintance showed me his paper, and openly proclaimed how it was just so much garbage, and that there was no reason I should have been marked down. That took guts and I thank him for it.
College, a place of intellectual stimulation? Hardly. As an ROTC cadet I was called a baby-killer on "uniform day" by a hippie under a giant peace sign draped from one of the buildings. I told him I didn't kill as many babies as him and his pro-choice types. That shut him up.
I hope the above article, my experiences, and the way people seem to become brainwashed sheep after being exposed to the education system help people remember to not believe everything the teacher says. Of course if you are reading this you're probably already aware of the problem, or else looking for a way to turn me in for being intolerant of the ideas of others or some such nonsense.
Challenge when you think you can get away with it, but ultimately you may have to strategically bide your time spouting the propaganda you loath just so you can get better grades. Think long-term. Pick your battles well. Live to fight another day in a more effective way. ;-)