Nylons are for women who don't look good with bare legs.

I wear them very, very occasionally for fancy-dos or if I need to get to an interview without having had the time to shave my legs but, really, once you've been on HRT for a while, assuming that you don't have crazy-dark hair that shows up after a single day, shaved legs and bare skin are perfectly fine. I know a few women who wear them on a regular because of their job (government employees, especially at the upper levels of management, bankers, etc) but, really very few women I know wear them at all.
Tights, on the other hand... well that's a different story. They're fashionable right now (still kinda sorta fading out a little but still 'in') and they're available in really cute patterns for daily wear and some outrageous ones for having fun with. (I play derby so I get to wear all the crazy ones for the fun of it.)