My experiences have been very different from Kaveh's.
Ive tried this be open minded thing before, going as far as to make cd's for people who showed an interest in music. This was usually a "musician, or guitar player i met at work who, as it usually turned out, had never heard of a chromatic scale, and the response was always the same, "it all sounds the same", "why is he yelling?", "its all just power chords" or my favourite "i used to listen to slipknot and system of a down when i was a kid, ive already listened to this kind of music before". Ive even gone as far as too show people some interesting electronica, usually this leads no where as well, "why do they repeat the same bar more than 4 times?". This does not mean we should not be trying to expose people to great music but let us have realistic expectations regarding the outcome. Most people want music that panders to their emotions or lets them escape from their own shitty lives for a moment, not reality confronting and exploratory death metal, black metal, electronica or classical.
This kind of experiment would certainly reveal the hypocrisy inherent in most peoples notion of being open minded- which usually just means be a non-threatening, "progressive" liberal moron.