Who said it should be a tutorial? I agree on that point it's not a how to, and a tutorial is probably a contradiction for the topic. That doesn't mean it can't

Who said it should be a tutorial? I agree on that point it's not a how to, and a tutorial is probably a contradiction for the topic. That doesn't mean it can't discuss practicalities. Plenty of advanced papers, blog posts, documentation, experiments, whatever, discuss engineering realities because they feel like it. The reality is some things are less intuitive and require more outside the problem thinking than others. If someone is writing about how binary trees work alone, not concurrent programming as well as is done here, there's little point to considering applications because it's simply useful to know and apply the concept so often. However this one is an edge case, and even when you need it I would doubt many seasoned engineers wouldn't still benefit from contextual considerations from the author.