It's because you barely have any STEEM in your account. The more STEEM you have the faster you can get more. The rich get richer. And it works in momentum. You do get rewards for voting on posts but since you have little STEEM at the moment you will not see any results from that. But once you have 100 STEEM you will start to see curation rewards which will excite you more and see that your time is worth real money compared to other platforms.