I've read 3 pages of rationalizing, and people dancing around the issue, when the answer is plain as day.
It's not because D&D was maligned in the eighties that the hobby has such a bad reputation. The only reason is that a vast majority of the people who play the games are nerds, period. There's no smoke without fire, and stereotypes are always true, else they wouldn't have become part of common worldly wisdom in the first place. Of course people protest when they're in the receiving end, but it doesn't change the facts.
Guys who were hardcore fans of intellectual and introverted hobbies demanding huge time investments, like chess, were universally deemed as losers well before any D&D smear campaign.
That's the only reason why. Introverted guys are deemed as losers by society, because a man's worth is entirely determined by his ranking in the social totem pole. An intellectual man who doesn't also have status and power to go with it is deemed a loser too. We still function on the DNA of our prehistoric ancestors, an era in which for men dominance, physical strenght and manliness were all that mattered. They were the ones who sired children and got to pass their genes, while their subordinates were weeded out of the gene pool.
The qualities deemed attractive are those that will allow guys to pass off their genes according to the standards of our prehistoric ancestors. It's plain to see that if you're an hardcore RPG fan, you have far less chance of having dozens of friends, of having a high status job, of being handsome and muscular, of being married, of possessing anything that our brains are hardwired to make us admire.
It's especially bad for RPGs because the introverted guy stigma is combined with that of escapism. If you fantasize about escaping reality, it's mostly because society and life have dealt you a bad hand. And it's even worse for heroic fantasy games because in fantasy men are blessed with powers and become heroes revered by the world's inhabitants. Fantasy games are based on European folklore, on the epic heroes of legend part of the fundational myths. They were the embodiment of the ideals that the men were then to strive for.
If someone has a fetichism over that it's likely because he fantasizes about being everything he isn't in real life, and of living in a world where he is not only welcomed, but where everyone needs him, admires him, and where he has the possibility to accomplish numerous exploits.
Many of you in this thread confess to instantly perceiving RPG players as losers the instant you witness any telltale sign of being a fan of the hobby. I admit that it's also the first reaction I ever have: "That guy must be a social outcast."
All of this is simply peer pressure and evolution at work, so there isn't anything wrong with spending a lot of time playing PnP games so long as you don't neglect the other aspects of your life. But for these reasons, as long as role-playing games exist, they will come with the stigma of loserdom, period. World of Warcraft is eclipsing everything else, including D&D, as to what most people instantly think of when they think of RPGs, and the stigma is still as strong as ever. Mention to anyone that you like WoW a lot, and instantly they'll think of you as a loser.
It's also true that there is a complex with hedonistic activities in our society. We are supposed to work hard and take care of our family above all, less we are perceived as irresponsible. Someone who has an inordinate amount of time to spend on hobbies has way more chances of being a social outcast because if he has so much time to spend on entertainment it's because he has a void to fill.
It's hard as hell to orchestrate PnP games because when you grow up no one has the time to dedicate a whole evening every week to a hobby.
I'm sorry this isn't meant as an attack, and I don't try to be hypocritical (I would say I am a loser myself), but to me it seemed like the elephant in the room.
