Because the truth is painful. People don't want to believe things are bad. People will fight tooth and nail to hold onto their perception that we are living in some sort of utopia and that everything is sunshine and rainbows.
I don't blame people that want to look the other way...it's not a pleasant sight.
It's sure ain't easy but if you take a look at the history of mankind it sure is paradise. War and famine have has been the standard, things we complain about are totally different now.