Some people see this as a reason to stop talking about faith with certain folks. It’s really about not letting arguments drag on once they turn into attacks on what matters most.
Jesus still answered the Pharisees, even when they came at him hard. So maybe it’s about picking the moment instead of cutting people off for good.
Proverbs 23 puts it plainly, don’t waste your breath on fools. They’ll despise the wisest advice you give them. Same warning Jesus gives in Matthew 7:6.