Tweens buying power

Apropos of the Luthar presentations is this NYTimes article from 4/22 about the huge increase of buying power among kids aged 8-15:

Wendy Liebmann, president and founder of WSL Strategic Retail, has studied consumer behavior in retail stores for 17 years for her How America Shops survey.  [She was astounded to find that] parents said 75 percent of their children under 13 had some say — always or occasionally — on the purchases of home décor for their own room. Forty percent had some say in the skin care products they used, 45 percent on hair care products, 65 percent on sneakers and 58 percent on jeans.

Maybe I'm too much of a "modern" parent because this doesn't seem out of line to me.  What's wrong with letting your kid pick their own sneakers?  My mom used to bring me to the shoe store and let me pick my own shoes -- within a specific price range and utility of course.