When trying to make a case for some position or idea, we frequently encounter questions which challenge the coherency or validity of that position. When we are able to adequately answer those questions, our position becomes stronger. When we cannot answer the questions, then our position is weaker. If, however, we avoid the question altogether, then our reasoning process itself is revealed as possibly weak.
Reasons, but a common one may be a desire to avoid admitting that they might be wrong. They might not have a good answer, and while “I don’t know” is certainly acceptable, it may represent an unacceptable admission of at least potential error.
Another possible reason is that answering the question might lead one to the realization that their position isn’t valid, but that position plays an important role in their self-image. For example, someone’s ego might be dependent upon the premise that some other group is inferior to them — in such a situation, the person might be strongly inclined not to directly answer questions about the justification of that alleged inferiority, otherwise, they might have to acknowledge that they aren’t so superior after all.
