Racism, by its simplest definition, is the belief that race is the primary determinant of human traits and capacities and that racial differences produce an inherent superiority of a particular race. (wikipedia)
So, yes, this is racist. Is it hateful, no, but some of the comments are from both camps. THAT is why video's like this are harmful. They inspire hate (whether you think it is justified or not) from both sides. Yes the content is funny, they can't dance. But to package it in such a way that it label's all white people like that is harmful and wrong. Justifying it by saying that it happened (or still happens) to any other race is also wrong, and harmful. That will just perpetuate the hate and cement the divide between races. It's not the fact that you don't find it offensive to be called a name based on your colour, it's the precident that it sets (as black people are well aware of). Wake up, everyone.