You are right. True. Well I guess on FB you get at least likes for ego boosting. This can be a huge deal for some people. It is addicting. After a while you embrace the benefits of likes and you share more and more detailed, more personal, more intimate stuff. You may end up naked.
When I look at Steemit, more or less all starts with cents. Human greed for ego boosters (likes - one way or another) can go wild sometimes. Like you said - it's not all about the money. But with money and greed combination we can expect scams, self voting, flagging others, begging for return voting ect. On one hand we love being exposed, on the other we would like to keep our privacy. Hmm.