Racial segregation was mainly enforced because of the pride of the race that considered themselves "superior". Racial segregation, even though it has been demolished, has stuck through the lives of African Americans around the world in many ways. A lot of people are quick to judge people based on their appearances, and despite the demolition of segregation many African Americans to this day face racism solely for the color of their skin. If I was told that I couldn't go to certain places, I would obviously feel like it is unfair. No one should be judged based on the color of their skin, and no one has the right to ban someone from entering a place based on their race.
Hope this helps :)