11Handicap, as a teacher of mine used to drill into us, "Consider the source."
YouTube is a social site with NO qualifications for posting. They have rules on what can and can't be posted, but anyone with a cell phone camera and a desire to be seen can post a video. So the answer is "No, not everyone is that mean" and try to stick to the independently-respected channels, listed above, for information to trust. If in doubt, stop by here and ask - we won't treat you badly. :-)
“Malo periculosam, libertatem quam quietam servitutem." (I prefer the tumult of liberty to the quiet of servitude.). Thomas Jefferson
"All that is necessary for the triumph of evil is that good men do nothing."
-Edmund Burke, Loosely translated from Thoughts on the Cause of Present Discontents. (1770)