The things they are demanding have to do with correcting injustices that still exist in American society such as racial and educational segregation and racism in the criminal justice system among other social problems. 
The Civil Rights Act of 1964 is only two-generations old. Legal discrimination endured for many generations and de facto discrimination and bias are still rampant today. 
Old ignorant white people like the ones commenting here should just go back to their booze pills and ignorance and leave the younger generation of non-white, educated kids alone. Isn't it enough that young people have to deal with the mess caused by ignorant white old white people?