Well, that's why the most important part (when using auto voters) is to pick wisely the members you would put there. Meaning, you have to know the quality of the content they provide (through some previous times), their posting frequency and many other things.

Regarding the platform itself, I can't entirely agree with you as the platform was not created as some possible future replacement for Facebook, Twitter or similar social sites and accordingly it doesn't compete with them.
The goal was to gather quality content providers (bloggers) that would be more easily found and rewarded for their work than they would be otherwise, even if they are running their blog on own domain and being paid through some GoogleAdsense or similar advertisements displayed on their site, and above all being lost among billions of websites out there and without some serious investment unable to reach some higher place in Google Search.

Therefore and from my point of view, Steemit is more some kind of combination in between some blogger community site (e.g. like free WordPress or Blogger.com would be) and some social network site. Accordingly, the expected interaction would also be somewhere in between those two.
And the biggest difference from both is that it pays its members for their activity.

In the end, last but not least, instead searching for interesting content among Trending, Hot and Promoted or among some popular tags, consider trying in the New!
Although there would be without doubt a bunch of worthless (one-photo, one-video, a lot of copy/paste, plagiarism etc. articles), you may find some true not yet discovered gems there.
Personally, I'm trying to take a peek there as often as I can. 😉