when it's obviously gabbage

i only get angry when foreigners diss Africa not when my fellow Africans insult it

It is the same way your family can say really mean things but an outsider can't. Because you believe your family's opinion or assessment comes from a place of love. It is just normal human, it is easier for a white person to explain racism to another white person than for a black person. If a black person tries, more often than not what you get is their defence will be up.