I'll be blunt, since you asked a very blunt question, and hopefully appreciate an honest reply!
LONERS ARE LOSERS. They sit at home and play video games and masturbate to night elves in World of Warcraft. That's the general though anyway, hopefully this isnt you!
Women like men who can actually carry a conversation. That doesnt mean talk a lot, it just means be open, honest, communicative, and not such a turtle shelled limp dick.
GIRLS LIKE MEN WHO HAVE BALLS. Loners generally dont have any balls, they never take control, they never have much initiative, etc....> Plus, if your always alone, how would that leave a woman for her time? Always having to have the guy hanging around going "bebe, ima so bored, plz blow me or do sumtin wit me", or having a guy who has a few hot friends.................... Hmmmmmmm.
Shorter reply than anticipated, a friend just knocked on my door, but this is the general idea!