This is kind of funny reading all of these.
You can see who has the open-minds to music and who doesn't. They are a group formed by industry and yes they didn't know what metal was before but now they love what they are doing. Everyone has their different taste in music. No one can have a shitty taste in music if it's what they like. Most people fail to realize that modern rappers who write shit still make, then you have people who are fans of BC13 and BotDF.
I'm sure not everyone in the Babymetal fanbase really cares if they are young teenagers, because they make good music. Please excuse that not everyone has the "Great taste in music" as you do. We all have opinions in what we like to listen to. I honestly don't think that the fans of babymetal shouldn't make a big deal about this because of bands like Metallica, Cannibal Corpse, etc like their music. They have more supporters than they do haters.. I am sure they will do fine with the support of their fans.