The disdain for natural black hair is ingrained in western society. Only relatively recently have things starting to change with the natural hair movement.
Her creators wanted her to be beautiful so natural hair wasn't cutting it for them as it was not considered beautiful. Black people have lost jobs and told not to come to school because their natural hair was deemed "inappropriate" or "unprofessional"
In other words, screw the straight hair. If someone wants to give her an afro, cornrows, or dreadlocks during a run then let them. It would be tons more interesting than the straight hair.