My upvoting is often to encourage the writer and not specifically geared towards encouraging content that makes Steem more attractive.
I do a lot of this, too, especially with my bot voting. I view it as a form of patronage, or sponsorship, so I do think that type of voting can also help to grow Steem.
Your rss-feed is often too much to read all (for me)
That's why I put the little "head lines" in. I figure that readers can look at the opening description, and decide what they read. If there's nothing there, they're in and out in 10 seconds. If they want to learn more about one of the topics, they can scroll down, and read the headlines and micro-summaries that interest them, and if they still want more, they can click through. It's all designed to give the reader fast access to new information from the Internet, with an easy path to learn more.