That confirms my belief in the usefulness , long-term, to keep making long form posts even if they don't pay out very well right now.
As a platform Steemit.com will keep climbing in Alexa rank and its contents will keep ranking higher and higher in Google's search results (unless they start messing with it on purpose)
Long form content will naturally contain keywords, and google's objectives are to present searchers with quality links, so time spent on page etc. will sooner or later weigh heavily in the search rankings.

I think it can't hurt to optimize your articles of course but to much obsession to game the algorithms is probably futile since they keep changing it to defeat "optimization" tricks that do not lead to quality content.
Its a very Darwinistic system.
Playing too many games with SEO will probably hurt you in the long run IF you do it at the expense of quality content
See:
https://hallanalysis.com/2017/05/26/seo-over-optimization/

My goals for Steemit is to find an audience of true fans, preferably a 1000 of them :)
Steemit.com I think is the first platform in a long time where I see that I have a better than average shot at achieving that, because currently the quality of comments is outstanding and that will automatically improve SEO value too. That is the real multiplier.

People chasing upvotes through memes pictures etc. are playing a very short term game. They are not building a portfolio that will pay off for them as you describe in your post.

I see the current reward distribution as an anomaly, things are starting out and are a bit crazy, I see fantastic posts not getting anything and trivial ones getting ridiculous rewards.
"Good on them" I say but long term they can't count on that continuing.

Steemit.com can become a hugely rewarding platform if distribution goes to consistently tens' of dollars per good post and a few hundred for outstanding posts.
If you have some predictability about your earnings, you can make this a full time job.
To get that predictability you'll need an engaged following that is actively commenting or spreading your content...
We're not there yet, but I am betting on that becoming a reality and will keep pluggin' away at my (maybe too) long form posts...