Those who claim to be the most open-minded are often the least. Case in point: has a devout Christian ever accused you of being closed-minded* because you're not Christian? Do they seem so very open-minded if you should attempt to discuss the tenets and beliefs of Buddhism, Islam, Judaism, or Zoroastrianism on the same plane as their own religion? Suddenly, that door shuts real quick.
*I love this video, despite the fact that it clings to the belief that "close-minded" or "closed-minded" is the opposite of the word "open-minded". It isn't. The proper word is "narrow-minded", although I sense that will cease being true in another few years due to "common usage". The English language is very open-minded.