Words are important to humans. People can be offended by words alone. Humans especially value names. The quickest way to insult a person is by intentionally using the wrong name, or a diminutive form, or mispronouncing it. The same applies to names for groups of people. Humans are expert at grouping populations into specific named collections (see Boundary Issues) and then defending the names of their own group while finding inappropriate names for others.
I have difficulty being offended by words or misused names. I depend much more on a person’s actions than words, but I have learned through a lifetime of careful observation that humans are different.