Because mine refuses to!
She is 10. Last summer she mostly wore converse hi-tops, this year it's Adidas superstars which are pretty much her only out of school shoes.
We're going to Europe on holiday in August, it's going to be hot. When I broached the subject of sandals with her, she said 'no way' (and that's for ANY sandals).
Her feet are going to be very hot in trainers. Are sandals seen as really uncool now??