Tights are very warm. I don't see much difference in this than microfiber long underwear for men.
I guess the difference from my point of view is what you wear that is visible. I used to wear a cup and a jock when I played football, but wearing them on the outside was, well, just not done.
Think purse and man bag. What something is called can make all the difference in the world :)
Note to the folks selling these things: Just don't call 'em pantyhose.
Increased temperature in the scrotal region from wearing pantyhose will hasten the demise of French sperm and thus usher in the coming Islamic horde the faster (Muslims wear long skirts don'tchaknow, plenty of ventilation). Oh well, French sperm probably didn't have much future anyway.