The appeal of feet is that most women have fucked up feet, so when you find someone who has really sexy feet it's arousing.

I think guys with foot fetish don't like all feet, but only sexy feet.

It's a bit like boobs. Why do we like big boobs? Because they are rare and we feel "cool" when we get the rare girl with big boobs (who isn't a whale).

Rarity is what makes something precious, like gold.