High heel fetish is nearly universal amongst men.
The structure of it causes women to stand in a particular way more reminiscent of a "breeding stance". (the but is propped up, and women are almost in a bending over stance) you might not have realized, but this is why they are so popular, and sexist expectations require women to wear them in many professional environments. to do otherwise is somehow "unprofessional"
It is why they are so uncomfortable to wear. and it is disgusting that he is perpetuating this onto young female characters who logically would NEVER NEVER NEVER wear them because they are the shittiest shoes possible for battle, especially for ninjas.
The artist should be smacked in the mouth.