Not to show what music really is.
Young girls will probably really like One Direction in a heartbeat. Problem is, is that they probably don't know that better music exists. People 16 and older will probably either be discovering or know better music. Younger people will probably only be focused on pop music. (Realize that I said "probably") They probably like One Direction because of looks, not musical talent. Parents, I recommend to not show your children this music. You can easily show them the song Yellow Submarine instead of You Don't Know You're Beautiful. So, why not? Show them musical diversity. Classical, metal, surf, jazz, all sorts of music. See what they prefer.