A person who habitually looks for faults in others is often referred to as a "fault-finder" or "critic." Such individuals have a tendency to focus on the negative aspects of others' behavior, actions, or characteristics, often overlooking the positive aspects or dismissing them altogether. This behavior is generally seen as negative and can be detrimental to relationships and social interactions. It's essential to practice empathy, understanding, and constructive feedback rather than constantly seeking out faults in others.