That's the kind of attitude Proverbs is talking about here. And some people seem to have that attitude all the time. But it's not a wise and godly way to live. The wise person pours oil on troubled waters. The wise person tries to avoid unnecessary conflict.
Wise people allow themselves to be wronged rather than fight back with harsh words.
Jesus told us to love our enemies and do good to those who hate us. To return good for evil. That operates in the area of what we say. A gentle answer turns away wrath, but a harsh word stirs up anger. The clear implication is that it's a situation where someone has said something in anger to you.