The details of what I record (in another comment[1]) might be idiosyncratic and uninteresting to you. Those details aren't important. The important point is that so much information belongs in multiple places. A single statement, let alone article or book, might regard all of economics, justice, common sense and beauty. It might be about parsing, Haskell, and keeping data types flexible. I'd like to be able to search based on any of those things.
If there were a clean distinction between entities and tags, existing solutions would be enough. But what if you want to draw a relationship between two relationships? Most sentences longer than three words, after all, are higher-order relationships. ("Birds #avoid beetles ##because beetles #are hard to digest", for instance, is a second-order because relationship joining two first-order relationships.)
The searches Mr. Borichevskiy imagined are, I think, good arguments for why you would want to be able to encode arbitrary higher-order information. I believe Hode is the simplest solution possible that allows it.
[1] https://news.ycombinator.com/item?id=21665698