That's like saying marketing is making remarkable products. It is true but incomplete and doesn't tell you anything actionable to get working on today. I'm sort of hoping my blog post said something that was true and non-vacuous.
There are all sorts of people who will fiddle with tags and whatnot to try to perfectly shape their site because they're scared/lazy to not make good content. But there is nothing that has a higher ROI on time than making interesting content. Sure, try to make interesting content around the long tail terms that you can optimize for, but at the end of the day, you have to make interesting content.
Also your statement about spending time on interesting content gives your the highest ROI is not true. Hollywood and the game industry prove from time to time that they can create hypes and market B quality productions and still make tons of money. This also counts on the internet. Content is evaluated by machines (Google, Bing etc) who determine if it is interesting or not. Doing A/B testing to test which landing page works best is better time spent than spending your time hiring people to create interesting content. Just changing your button can increase sales by over 100%.
Ask the developers in the appstore whats more important, interesting content or a position in the top 5.