Because just saying you're open-minded doesn't mean you have an open mind;
It means you can use your words.
And being open-minded can be easy;
It takes real courage to stand for something when everyone else is insulting you.
And deciding someone else is closed-minded could make you closed-minded;
If you aren't careful
You could become the person you didn't want to be
And insult a friend,
Or a total stranger-
And become the very person you claim to loathe