I saw that video, its one of the most accurate explanations on why what's been happening has been happening.

In normal arguments, like even in kindergarden, when two kids are arguing like arguing about colours

"Blue is the best colour"

"Nu-uh, all the colours are the best!"

"The sky is blue, its above all the other colours, the sky is so big, so the biggest colour too, thus the best!"

"No, you're just stupid for thinking that!" Shoves blue kid to the ground

He had the opportunity to say green was just because all the grass is green, all the life is green, that red is cool as fuck because its fire, if he told the other kid red was cool because fire is freaking awesome he could actually convince the kid, but instead just resorts to violence instead of proving his argument. All the other kids see him as the kid who shoved another kid to the ground for his opinion, and that kid now feels the need to fight back.

Its a simple example, someone's probably going to respond with "but still nazism has no excuse" But that's not my point, my point is regardless of what the topics are at hand, its instinctual to see action > thought. And you've made more enemies in that kindergarden than before you shoved that kid. Nothing unites people more than a common enemy.