..i dont understand

I was watching a speech that Adolf Hitler made on youtube and all the comments were like
"omg i looove hitler<3"
"what a great man!"

..I'm learning about the Holocaust right now and
i dont think people really
know what hitler did?..

He was the cause of the slaughter of about 6 million jews and about 5 million other minorities,
i honestly dont see why he's still looked at as a good person in the eyes of people. XD