Now, this is the guess on my half, but maybe the reason that sock garters are so sexy is that they're usually on the thighs (which many see as an attractive part of the body especially in recent years.) Or the bridal garter has been interpreted a symbol of defloration since the groom traditionally removes the garter. But again that's just a guess on my half.
Good analysis re the garters, thanks! I was thinking more of male sock garters on a 'shapely calf', as the saying used to go. My guess is that the same analysis applies to men, in that well, if we see their sock garters, we know their pants are off, ha. Or the trouser legs are rolled up to go in wading, or something.
Do people still use sock garters?
I dont even know there's things like sock garters.