Red carpets and high heels: I take guilty pleasure in checking

[enlightenment]

2. The problem is with the word "sexy"

Generally, that is something defined by the viewer, not the recipient of the view.

High heels throw women's 'assets' into high relief - an exaggerated 's' curve of tits and bum. They make legs look longer, too. All designed to attract attention; attract a mate.

There are many, many good looking, comfortable shoes out there, but the vast majority aren't sexy, nor will they be as long as sexy is perceived as "ready to have sex".