Everybody gets "open mindedness" wrong

 Open mindedness is generally a good thing, but it's also among the most misunderstood principles. The point about open mindedness is not to permit every opinion or to forbid people from expressing "bad" opinions, it's to promote the acceptance of humanity. 

So, for example, racist opinions are "bad" not because there's a divine code stating so, but because racists are generally against the acceptance of humanity and want to impose a hierarchy on it. On the flip side, people using "open mindedness" to censor "bad" opinions on, say, fiction, are also applying the principle incorrectly, because they've just decided that the people having different opinions from them are "wrong", thus subconsciously applying a hierarchy to humanity.

This is also key to applying it correctly when dealing with tangled issues, like talking about the sexism prevalent in some portions of Islam without coming off as an Islamophobe or talking about bad things normalized as part of a "culture" without implying the people of the culture are innately bad. The issue is not in the positivity or negativity of opinions, but rather the application of hierarchy, whether it be long established or newly made.