I agree that upvotes are hard to get, and that it is frustrating sometimes, but I think it is expected and is not really a problem. If people rarely upvote, then the upvote means that the answer/question was really good.
If you look at similar sites like stackoverflow.com , for example, it is not uncommon to see questions with 1k+ views and maybe one or two upvotes. Here the community is much smaller and questions have normally less than 100 views.
I personally think that upvotes should not be given 'for free' and only good/useful questions or answers should receive them.
I think the only possible 'solution' to increase overall upvoting is to upvote good questions and answers yourself, making it more common and hoping that people would also upvote more often.
Another possible option would be for moderators to comment on answers that were obviously useful for the user, and that received no upvote, reminding the user to upvote. For example, when the user accepts one answer and does not upvote, or when an user comments on an answer giving positive feedback, but the answer still has 0 upvotes.
But again, I think that few upvotes should be a frustrating only if you are never being upvoted or if the sole purpose of your answer or comment was to get points. If you answer or comment to genuinely help, I think upvotes and points should come as a consequence of your help.