Unfortunately, it has become a term used by condescending to describe themselves or to mean "you should agree with me."
The irony of term being that modern psychology disproves that people are incapable of being truly open minded. Therefore, if one was to claim that they are open minded, they must be willing to acknowledge that they are not open-minded.
Lindsay: You should be more open minded.
Elise: So, in other words, I should agree with you? You are aware you are not being open minded.
2. Politically correct synonym for "gullible" used by New Age quacks who want to sell you a bill of goods.
Open-mindedness is a virtue, but when dealing with New Age salespeople it is important to remember that if you keep your mind too open, your brain may fall out.