The rewards are not just for content. They're mainly for networking, which is both a skill and work, too. If I see some of the folks that earn a loooot more than I, I look at the network they established. Their consistency in posting and commenting. I was lucky to find mentors here that pushed me into the right direction, so I get some rewards for my posts, which I do find in line with the network I established.
Not with the quality, though. Sometimes I do a post that I really like a lot, and it doesn't draw any attention or up-votes. Sometimes it's the other way around, I do a good post, but not excellent, and suddenly there's a whale voting on it, followed by a whole trail.
Hence my conclusion that it's the networking. And no, hive doesn't own me any rewards. It's a nice extra, and I'd probably engage a little less if they weren't there, but they're more of a motivation of becoming better and working on my contributions.