I agree with @Jeff Atwood that we can't do much about this particular complaint (in the OP) without specific examples, but even in their absence this is a useful conversation to have and there are effective things we can do to make this site more inviting.
More generous voting on the part of users, especially voting for questions, could help.
At a minimum, I would hope that if anyone makes an effort to answer a question that they upvote that question (if not, why are you even bothering to respond to a bad question?) and, similarly, that anyone posing a question make an effort to upvote every response unless it is particularly bad or just dead wrong. (I am constantly surprised at the number of questions that get fewer votes than replies and the number of replies that are at least partially valid but get no votes at all...)
Think about it: if you read a reply and upvote it, that's +10 points for the respondent. If you move on without upvoting, that's +0 points. If you downvote, it's -2 points. Thus, not voting is 10/12 = 83% as bad as downvoting! A similar calculation applies to votes on questions. As a rule of thumb, if you're an active respondent, you should find it easy to put as many points into play as you receive: your votes:points ratio should be at least 0.1, more or less. If you're an active reader but don't respond much, you should have no trouble multiplying this minimum ratio several fold. Go inspect the users page to see who's meeting these criteria. Not many. Most of us are guilty of undervoting.
Now consider this situation from the point of view of a newbie. She posts a question and gets few or no upvotes (or worse, downvotes). The page shows dozens of views. Ergo, the (vast) majority of viewers think the question is either bad or very bad. Her natural conclusion? This community doesn't think much of her or doesn't care for what she's interested in. It goes downhill from there.
I think that until this situation turns around, this particular SE community is going to have a hard time getting into a sustainable mode.