Of course all people have bias, but I think systemic bias, deliberately trickling down from advertisers, board of directors, to media ownership and to editors... that is what shapes the idealistic reporters who might wish to find truth, into a state of self-censorship based on the expectation of being edited into non-threatening, status quo supporting, corporate approved 'news'. whew.
I think many reporters learn what gets them in trouble, and what doesn't at an early part in their career. Certain words, descriptions are off limits, certain angles of a story, certain situations (a strike, environmental law, capitalism actually hurting people, etc) are spun so as not to alarm the herd into critical thought. Or of course, bullshit celeb stories instead of news...OMG, Anna Nicole died! I forget what I was talking about, did you see her dress?