"the recognition that social groups and culture must be studied and understood on their own terms before valid comparisons can be made ." This definition suggest a level of objectivity on the part of the researcher or individual observing that cultural group.However,subjectivity seems more realistic than objectivity because most people tend to use their own culture as the rubric for which they judge every other culture.Then is cultural relativism possible to a full extent ?
It is difficult for people to fully appreciate and respect the culture of others without examining history and the common origin of all people and their culture. Through this they can better account for the differences and address their own biases. In the academic context(although not only there) persons study others without necessarily having examined their own ideas and context (cultural, religious etc) and as you hinted carry this into their own study. Apart from making judgments these also come with blind spots and limitations to how one can understand and gather meaning from what persons do and experience and gain from these experiences. So indeed to come to a position where one can appreciate and respect other cultures, one would need to be willing to examine their own position, idea, biases and where they are coming from and how it connects with all people.