An interesting proposition, to be sure. I wonder what this information would really tell us? For example, absent the long promised "communities" feature, Steemit has somewhat "self-organized" into loosely shaped communities: Bloggers, artists, photographers... various initiatives. Scraping the data shows us the community sentiment as a whole, but each micro-ecosystem has its own objectives and ambitions.
This untapped power can allow bloggers to adjust content according to what their followers actually want.
Well, I have a question, though... let's assume that I have built a following around "psychology and self-development;" knowing that the "most popular" trend is "smartphone apps" isn't exactly going to help me build my following in a completely different area. Or maybe I am missing something about the scope of what you're proposing?
Knowing more about your followers helps you a lot when it comes to providing content.