I do not believe that more precise feedback would help much. The experience of most social networks shows that people rarely care to provide more feedback than a "like" or a "dislike". In the olden days there were social networks where people could rate photos by setting 1..5 stars, and as far as I understand, most people would either put 5 stars or ignore the photo. 1 star would correspond to "flagging".

In principle, there is nothing wrong with counting upvotes perhaps weighing them. If there were no extrinsic motivations for upvoting, it would be a decent indicator of content quality.

Unfortunately, and somewhat paradoxically, the financial incentivization system of Steemit, although conceived in the hope of raising content quality, plays a lot against this goal to a large extent, forcing way too many people to focus their efforts bluntly gaming the system rather than expressing themselves creatively.

This is even worse with curation rewards, where the current system motivates "curators" to upvote posts based on their author and current upvote numbers, not caring to read them through.

There are many secondary indicators of quality (how many people read the post out of those who saw it, and how many people out of those who read it upvoted it, how much total time people spent on the post, how many comments it attracted), and rewarding the curators for being able to predict a mix of such indicators could, in fact, force people to actually pay attention to the content, rather than the current upvote $ number. Same for the authors.

Steem is not designed to maintain a value pegged to dollar. Steem Dollar is (although it's not perfectly stable, as you may note).