What I found out about news?

I grow up watching news and sometimes I wonder why the news they are reporting are heinous, just then after a long long years of wondering it is answered. My professor in radio performance told us, that news are based on people's demands and to sell, not because people wanted to know about what's really happening in this world.  He's a radio announcer and a news reporter in a popular network. At first I thought that maybe he's just misleading us, but hello why would he do that. He said that he wants us to be a good journalist, that's why he's telling us that. People watched news not to satisfy their curiosity, but to be entertained. They want news to be catchy, they don't like good news, who would be interested anyway if two men reconcile after a fight? No one. That's why journalist and media practitioner take news that are odd, sensational and exaggerated, because that's what sells and that's what people like, so he told us that if ever we made it, we should give what is right and not what people  want, because a good journalist/media practitioner knows what is right from wrong. Journalist are public server and as a public server we must know the right thing and not the wrong ones.