You're voting people who have given you liquid Hive, you're not giving them part of the curation rewards, just their value back over time in the form of small votes over many posts. That's the issue.
That is incorrect. Take the 50% curation the HSBI account gets. Now do the math to figure out what that is per share of HSBI. They then receive an upvote equal to that. So you see, the upvote is not their money coming back, but it is the curation on their upvote. There is no difference between this "upvote payment" and the "curation payment" they would otherwise have been getting if they had powered up the HIVE themselves.
@josephsavage correct me if I'm wrong.