I also struggled to find an interesting new thought in the article. It was a bit nihilistic to just say that there is no dividing line and leave it at that. Great... there is no clear-cut line, so what?

Categorization is a tool for scientists to use for comparison. It's kind of like k-nearest neighbors learning. We have to draw the line for categories somewhere initially, then we adjust where that line is over time and add more categories if needed.