As a guy, I can't identify myself as neither quiet nor talkative. Sometimes I'm in a talking mood, and sometimes I'm not. I often would rather not be in the center of group conversations, and I prefer to listen as opposed to talk, unless it's a topic I feel very strongly about. Nonetheless, if nobody is talking I like to break the ice. Sometimes people like myself get labeled as "quiet", just because we don't always want to partake in conversations and aren't consistently verbal in all situations. That's not a fair or honest label.
Besides, "quiet" is a misleading adjective. I would want to find myself a girl who isn't loud - in the plain sense of the word - but does have a pleasant and playful personality and a developed sense of humor. I want someone who loves to laugh as much as I do, even if she isn't always the life of every single party. Just because someone is quiet doesn't mean they should be boring. Quietness is a personality trait, but being boring is a dilemma. People who are dating should develop their own personality, even if they don't necessarily stop being "quiet." Nobody wants to be married to a boring person, and that goes both ways. "Chemistry" does play a role in who finds whom boring/fun, but there needs to be something there for the chemistry to build off of.
I used to be super-shy when I was a kid, but I overcame that, and I find that it's helped me in countless ways. Someone is allowed to be quiet, but that doesn't mean they should be overly shy and impossible to hold a conversation with or have fun with.