Disrespect does not have to have a color attached to it. In this case, attaching color to unacceptable actions of a student just excuses it. When are adults going to wake up?
Although you are correct that the fundamental problem is a school run like a zoo instead of a place that demands discipline, you are wrong about it not being racist. These black students consciously choose to charge their disrespect with racist remarks. Would it be better if they were screaming "I hate school" or calmly saying "I hate white crackers like you." ? Personally, I find the latter to be the more disrespectful and so do the students, although they appear to like combining both.
I see more and more black racism as time passes.