Specifically I point to the progress we've made in the past generation because it concerns me to see young people taking it backwards. Things got better by not focusing on someone's race and promoting individualism. Going back to demonizing people based on race, whether it was black people in the past or white people now, that breeds resentment, creates division and isn't helpful to anyone.
I understand where you're coming from. You're right, if a black person does everything right and go above and beyond, they can 'make it' in this country. The problem is, a white person 'makes it' in this country a lot more often and a lot easier than any given black person. There has been progress, but too many people see that progress and say, "yeah, the problem's solved, racism is over." Which is what it sounds like you're saying.
Young protesters are saying, there is still a problem. Black lives are treated as disposable by both police officers and the criminal justice system at large way too often. And whereas they are held accountable to every time they commit a petty crime, their killers, like George Zimmerman, are not held accountable. They are angry because the system is still failing them and killing them, and saying that their anger is unjustified just amplifies that anger.
By denying the legitimacy of their protests, you yourself are perpetuating the system and the attitudes that they are angry about, and furthering the conflict.