
We generally fear, or mock, that which we don't understand. So let's take a look at what 'mantyhose' IS and what it's NOT (generally speaking):

It's also NOT a gay thing. From what I've read on a variety of blogs and forums, gay men for the most part feel about the same way about pantyhose as the stereotypical woman does. They don't like them and don't want to wear them.
It's NOT an attempt to revert back to fashions of the 1700s. If it's sometimes pointed out that men were the ones who wore the tights in the Middle Ages, it's only to illustrate that they're NOT exclusively a female garment.
It's NOT a secret desire to cross dress, either. Guys who are wearing the male hosiery on the market today (which does come with a fly, BTW) aren't typically combining it with other female items to start dressing as a woman.
It IS a recognition that men are as likely as women to have tired, achy legs due to poor circulation, and that support hosiery provides relief if worn consistently. Sometimes they're worn under jeans or other pants--sometimes they're worn with shorts. Sometimes they're in virtually invisible colors that closely matches skintone--sometimes they're worn in more visible colors like black or dark grey.
It IS a way to attain added warmth beneath outer clothing without the added bulk of long johns or sweatpants. Some guys can live with long johns, others prefer the thin fabric that moves with them.
It IS a way for athletes (especially runners and cyclists) to keep the chill off the legs when they first go outside--yet avoid overheating after their body temperature rises with exercise.
It IS also a way for those athletes to enhance stamina somewhat with the moderate muscle compression provided by support styles of hosiery.
It IS a garment worn for fashion in some cases, in that guys are recognizing they can successfully add them to a masculine outfit if properly coordinated (i.e., not as shown in the photo above, by the Eiffel Tower).

If you're a basically masculine guy in the first place, wearing legwear doesn't detract from it. Yet, if you're an effeminate guy it doesn't matter if you wear a Rambo outfit--you'll STILL look like a girly-man. (anybody here old enough to remember Michael Dukakis wearing the tank commander helmet during the 1988 presidential campaign?)
As with most everything, there are no absolutes. The foregoing statements represent the bulk of men who wear legwear today. Yes, there will be a few who will wear ostentacious patterns and colors out in public with shorts. Yes, there are gay men who wear pantyhose and like them. Yes, there are certainly cross dressers who wear pantyhose with their outfits, too. But, by and large those are NOT representative of the majority of men wearing nylon legwear--and on behalf of them I hope to shed a bit of light on the subject. Hopefully, this will cause more writers to stop and take a more reasoned approach to the "mantyhose question".