Cultural relativism is known to be the positive side of things. Whenever there are things that are happening, the positive side is considered to be part of cultural relativism. It can also show that people are very understanding of the different cultures that they will encounter even if it is the first time that they have been exposed to certain types of culture.
This is different from ethnocentrism that is considered to be a bit darker. This means that the person believes that he should not think about and respect the culture of other people because of the culture that he has, the culture that he is exposed to is the best one. This explains why cultural relativism is considered as positive while ethnocentrism is considered to be negative.