Of course, all racism is bad and should be condemned.
But the fact of the matter is that a white man expressing racism towards black people is representative of centuries of systemic racism. The crazy guy on youtube calling people to arms to kill whitey has no system behind him. He hasn't got a government and police force made up of individuals of his own or similar demographic.
Basically what I'm saying is that as a white person, I'm far more concerned about the damage to society being done by a racist white man who is willing to disparage the President of the United States based on his race than I am about a guy with a video camera posting on youtube about killing whitey.
Posted from my smart phone; please excuse typos or brevity.