When I take the time to read a post, to upvote it and to give a comment, I expect something in return!
For the last months I had the same discussion with a user I'm not tagging now to keep him from asking again "I have come here, now where's my reward?" just like he did yesterday.
My point rather is: tell the people not to come here for the money. But this idea is also fueled by the observation that Steemit attracts a special kind of people.
I think that everybody on steem should avoid to "expect" to be rewarded either for writing or reading. If you take the perspective of the author who wants to build up interaction, I think rewarding the readers that contribute quality comments is a good way to do so.