Because the average man wants to have sex. And therefore being a virgin means you've failed to get any. For whatever reason, hopefully self-inflicted, because at least then it's by choice. Or because you're not attractive. Or repulsive. Or uninteresting. Or you smell. Or whatever reason, but there is a reason. And it's probably your doing, maybe you're not going for the girl who offers it because she isn't "special"? Maybe you're scared of losing it?
Well bullshit, nobody is that special, and all you're doing is sticking your dick into someone, it won't last long.
Really not long, about a minute if you're lucky.
And no, I haven't lost mine yet, and i'm 21 and I damn well hate the thing.
Nothing special about it apart from the fact that you're a shit shag and are slightly more awkward in intimate situations.
And you're not asexual. You just don't have a sex drive.
Now go find that girl out there who wants you, because there is one somewhere, and you probably know them, if not now, then carry on and make the best of life before it ends, then when you find a girl you like, go for her, if a girl likes you, give it the best shot you can, it'll probably end, but you'll get another notch on the belt of girlfriends if nothing else, and more experience. Now, what's stopping you telling that girl you like that you want her?