That's very true. At some point, it becomes a self fulfilling prophesy. I think people look for when a specific person posts and automatically upvote it hoping to get in on the curation. I was reading the steem white paper recently and it seems that we are supposed to be downvoting poor content, but that somehow doesn't seem right. We don't seem to be a very good crab bucket (you probably have to read the whitepaper to get that reference).