Here's what I have discovered and figured out on my own.
Visual
Stockings, nylons, and pantyhose have a slimming and blemish-removing effect on the legs of the wearer. They accentuate the natural shape and curves of the wearer's legs and feet, which is appealing to the male's visually-aroused mind. Since they make blemishes (wrinkles, vericose veins, cuts/scrapes/bruises) much less obvious and sometimes invisible, they make the legs and feet of the wearer that much more attractive. It also lends to a subconscious sense of mystery.
Personality
A woman wear stockings or hose to show off her legs - it's as simple as that. Even if the sole intention is to mask or hide a blemish as described above, the purpose of stockings is to make the legs and feet more attractive, which is easily picked up on by her male counterpart.
Tactile
The sensation of running one's hand along a nylon-covered leg or foot is more pleasing, to many men, than that of along a bare leg. Dry skin, cuts, and other blemishes can make the bare leg or foot less pleasant to touch, whereas we all know that a leg or foot covered in nylons will be smooth and soft to the touch.
Ticklishness
It is commonly accepted that the foot is more ticklish when encased in a high-quality pair of stockings, more often than not. Someone with a tickling fetish will ALWAYS, without exception, have this on their mind when they see someone attractive in stockings. They may not always realize it, but it lends heavily to the train of thought.
Hopefully this isn't too impersonal - just my observations. 🙂