I like the idea, but I'm confused. Why go to all the effort to think about visualization methods, then shoehorn them into the shape of the chemical element peri

I like the idea, but I'm confused. Why go to all the effort to think about visualization methods, then shoehorn them into the shape of the chemical element periodic table, without even making use of the periodic structure of the table? Funny enough, "periodic table" isn't its own item on this chart. I think it would be more useful and interesting to group by type in some way, perhaps with a bit of tree structure. Which reminds me of a loosely related idea: I'd like to see a tree diagram of different tree data structures, where the tree structure reflects the relationships of historical development and/or data structure behavior...