@vipnate just wrote that both goes hand in hand. You read, comment and if you like it you upvote. Just upvoting I find time-consuming because I still have to find somethinging worth upvoting . Can be I'm different and my main problem is that I read too much?
I agree with all you say but the question is how to make clear that if you don't comment and only depend or hope for an upvote from SC this might not work out. What happens if the SCs stop for a month? All of them? What will happen?