It gets easier to understand when you realize most of us were bullied as kids. It becomes a natural instinct to herd together and protect our own. It's less because some of those people have media connections and more because those media connections happen to be people they consider friends and loved ones. At that point, emotional bias takes over.
Or, to put it another way, if somebody told you your mother was a murderer, would you believe him, no matter what evidence he presented? Even if he had a video of the event, it would be easier for you to believe that the tape had been doctored than for you to believe this person you loved could do something so terrible. At least it would be for me.
I'm not excusing it, mind you, just explaining it.